How to add ingredients to your recipes

I have the ingredients in my stock, but how do I add them to a recipe?

Go to the menu and select the recipe. In the upper right corner of that recipe box, you'll see a button appear that lets you assign the recipe to a specific chef. If you assign it to a chef with stocked ingredients that can be used in the recipe, it'll show up in the list. Check the ingredient and now it will be used whenever the chef cooks that dish. You should periodically check on your chef's inventory (you can use the staff panel) because stuff gets used up and there's no warning when they run out.