Recipe search by ingredients for home cooks

Your recipe app has 60,000 recipes. Each recipe lists its ingredients from the app's fixed list of 2,500, with 4 to 20 per recipe. Salt, pepper, oil and water are left off the list.

A new screen lets a cook tick the ingredients they have at home, usually 5 to 15. It then lists the recipes they can make with at most 2 ingredients missing. Recipes with nothing missing come first, then those missing 1, then those missing 2. Within each group, higher-rated recipes come first. Each result names what is missing, and the screen shows 20 results at a time.

Cooks will run about 300,000 of these searches a day, up to 40 a second around 17:00. Results should appear within 300 ms. Editors add about 50 recipes a week.

What do you keep for each recipe, and how does a search find and order the recipes for a cook's ingredients?