PlateUp!

After a lot of trial and error I finally got this.

I ended up doing a golden corral approach, thanks Skootie on YouTube for the idea. You can sometimes select Variety card with the franchise after day 15. It let's you start with the current cooking card and select an extra one. I started with Fish and after getting the variety card and losing I saved all of the -15% cards. Then starting with the franchise I selected Turkey. At the end of the run I got another Variety card. Again I kept the -15% cards and this time selected Dumplings. By the time I got to overtime on this 3rd run I only had 3 customer groups to serve.

It's a difficult run for sure.

That said I can share the achievement. Message me on xbox and we can schedule a time. All you have to do to share these achievements is start the day on day 5 10 or 15 in overtime and anyone in the game with you will unlock it. They are stackable so you will unlock all 3 if you are overtime day 15. No need to finish the day and you can save and return to HQ.

So me and a friend did this twice actually: once with the intent to get this achievement, and once on accident while trying to get XP for the Stir Fry recipe. I found Shire's guide generally helpful, but I wanted to go over both of my runs and explain in detail what we were looking for during the runs.

Franchise Choice

Note: When I say "reset" in this guide, I mean getting to at least Overtime 1, and then picking 3 cards to carry over into a franchise at the game over screen. DO NOT SCRAP THE CARDS FOR XP!

Our first franchise was fish, and we stuck with that throughout 5 resets. We had many different starters, entrees, sides, and desserts going by the end of it. Most of it was easy enough to make, with some annoying things requiring you to take out the trash (spiny fish in particular was annoying).

Our other franchise was meat pies, and we only reset once. Since we did this after already getting Overtime Day 15, we were able to get all the way to Overtime 20, and probably could have gone further. We also had good luck and all of our important items in the restaurant.

In either run, make sure you pick the largest and most open restaurant you can pick; you'll end up needing all of the space you can get by the end of the run.

Cards

Let's talk about cards. During a run, your goal is to get at least 3 -15% cards to reduce the amount of groups you get during the day. You want to make it to at least Day 15 so that you can transfer the 3 cards to the next Franchise, where you repeat the process to try and get 3 more -15% cards to add to the pile. These won't always be options though, so try not to pick other cards that are going to entirely ruin your work flow.
Example: we didn't like cards that altered the flow of the customers, like the one that gives a surge during the middle of the day, or the one where customers can arrive after closing time. On day 15, you will get one special card that you HAVE to take with you, and unfortunately, many of these give +30%, effectively nullifying 2 of your -15% cards. Try to look for cards like Variety, which doesn't give the +30%, and lets you make a new type of food at the next franchise.

The catch with the -15% cards is that each one will add variation to what you're serving. If you're not prepared to adjust to these variations, you can get overwhelmed quickly, so make sure your chef knows exactly how to make everything.

When you feel done with a run, let yourself lose and start anew, carrying forward with all of the cards that you've brought with you. By the 5th reset of our fish franchise, we had 20 something cards, and we had enough -15% cards to attempt to get to Overtime 15. When you do go for the attempt, make sure you still pick up all of the -15% cards you can, and don't be afraid to dashboard if the day looks like it's going to be a failure.

Items

To get to Overtime 15 (you just need to complete Overtime 14, then load the next day up), you will need to be on the lookout for a few items. For our setup, we had lots of different starters, entrees, sides, and desserts to serve. Here's what we looked out for, both during the prep runs and the actual attempted run:

-The Research Desk is a must as soon as possible, as it will let you upgrade items thrown into the Blueprint Cabinet.

-As the person who served the customers and cleaned the dishes, I found the Dish Washer was the best upgrade for the Sink, as it can clean 4 dishes at once while you go to do other things. If you have Napkins or the restaurant style where customers make no messes, you can put this anywhere.

-The Danger Hob was very important for getting all of the cooking done in time, especially early in the run for our soup starters.

-Tables and Coffee Tables were always nice to see, but don't have more regular Tables than you need. You can always buy the Tables and take away all of the chairs so the customers won't sit in them until you reach a day where you want them to.

-The Blueprint Desk (Research Desk upgrade) allowed us to try and get lucky and get a specific item (the desk will rotate through items as the day goes on, interact with it to guarantee that the item appears in the Shop the next day).

-The Copying Desk (Research Desk upgrade) allowed us to make 1 copy of any blueprint that we put in the cabinet next to it.

-The Frozen Prep Station, which is the only upgrade of the Prep Station, was by far the most useful item of both of our runs. This allows you to store 4 of one type of food to carry over to the next day (one Prep Station can only store one type of food, but having another one allows you to store 4 of something else). By using the Copying Desk, you can get one of these per day and have upwards of 10 of them by the time you get close to the end of the run. You'll be needing these as well, because the customers will have 3+options for their starters, entrees, and desserts.

-Both of the Counter's upgrades were decent. The Freezer was a nice alternative (for soup pots at least) if we couldn't get the Frozen Prep Station, and the Workstation helped things in the kitchen go slightly faster.

-An extra Blueprint Cabinet was nice to have if we wanted to store more than one item for later.

-The Trainers will let you move fast, which is helpful for getting dishes to everyone quickly. BUT, you will need to have the restaurant style that lets customers make no mess, or you will need Napkins that will have to be placed on every table.

-The Sharp Cutlery was nice for getting people out of the restaurant fairly quickly at the start of the day; this wasn't really helpful until later in the run.

-The Rolling Pin or Sharp Knife was nice for the chef to have, depending on what most of the dishes needed more.

-The Calm Painting is only sold on "decoration days", but it increases patience for the whole room they are in, which is a must later on in the run.

That about covers most of the items. Try and get the Hob/Dish Washer done early, then keep a lookout for the Prep Station. When you get it, upgrade it with the Research Desk, then try to get the Copying Desk to make a ton of these. If you're not able to get another Research Desk to upgrade, or the Prep Station isn't popping up, look for some of the other items, OR save a bit for some decorations.

General Strategies

Early on in the run, ring the phone all the way to the end of the day if the amount of groups is < or = the amount of tables you have. You will likely have very few groups at the start, and the early money is important. Beyond the first three or so days, ring the phone with discretion, and don't ring it at all when you feel pleased with your income.

When you're starting the day, have the chef start prepping starters, and have the server start putting any items like the Napkins or the Sharp Cutlery on tables. Do your best to keep track of where each table is at in their meal (starter, entree, or dessert), and try to clear customers quickly early on so that everyone who arrives throughout the day has a table to sit at.

If you're the chef, try not to get too far ahead on orders, and focus on keeping your Prep Stations stocked. If your layout is good, your server should be able to grab most of what they need without asking you to move something. Even then, you might have to help them get things like dessert out, depending on what you decide to do with the Prep Stations you can both access. Your job is hard at the start, gets easier in the middle of the run, and gets harder again towards the end.

If you're the server, speed and efficiency is key. Have an idea of where you're going next, and all of the things you can do while you're over there. Try to get plates washed when you have some downtime, as these can be a quick way to seat a new customer or two. Don't take everyone's orders at once; take each one at a steady but spaced out pace, unless you need to clear a lot of tables quickly. If your chef doesn't have something to make, try and find them an order so they can get started on something. Your job is easy at the start, and will only get harder each and every day.

Towards the end of the day, try to have one table where you go really slow with the customer's order. Use this time to mess with the Research Desk/Copy Desk, and fill up the Frozen Prep Stations as much as possible. When you're done with all of this (or you start to run out time), get the customer out and advance to the next day.

Conclusion

This achievement was surprisingly annoying to get, as it just took a good 10+hours of runs to get to the point where we could actually reach the end. If you're lucky, you might only take 2 hours or so, but otherwise, be prepared to grind out some resets for those -15% cards.