Catering orders can be for specific dishes or food categories in general. If it's a specific dish, you need to cook the needed amount and fill the box with it. If it's a food category, you need to choose a dish from that category, cook it and fill the box with it. You can only fill the boxes with 1 type of dish, so you'll need the full amount before you can see the "Fill" button on the box.
Each catering order has 3 normal order boxes, 3 category boxes and 3 bonus boxes.
You have a specific amount of time to finish the orders and this time might change according to the order.
When you tap on a box, you can see 3 options to fill the box as well as the rewards you will get from filling the box, such as the coins and XP.
If you already have enough of the dish, the Fill button will be green and you will be able to complete the box by using the dish. If you want to cook it first, you can press the Cook button and it will take you right to the cookbook. Alternatively, you can use the Cash button to fill the box right away without using any of your dishes.
Once you complete a row of boxes, the first row of rewards will be lit green and you will be able to earn them when you send the truck.
Once you get a catering order and complete it or send away the truck empty, a cooldown starts. Currently, you need to wait for 4 hours before a new order arrives. This time might change with the balance changes made to the game by Game Designers.
If you don't want to wait, you can make the next truck arrive immediately using Magic Sauces. Just tap on the catering building to see the order status and speed up the process! Alternatively, you can use one of the special cashiers to lessen your waiting time. For example, Hot Dog Cashier is a favorite of ours!
If you have not cooked enough of a dish, you can also ask for help from your club friends! Of course, you would need to belong to a club first. You can check out this article to learn more about cafe clubs. Once you are in a club, you can tap on the small hand icon to ask for help from your club friends!