In the category of “things I should have thought of but didn’t:” supercook.com - where you enter the ingredients you have on hand, and it returns suggested recipes. Neat! Turns out there are no known dishes that combine beets and eggplant. Who knew?
Aside from that, it’s a fairly normal recipe database, allowing users to upload suggested menus, recipes, and even pull things together into cookbooks. They seem to be having weird issues with their server, though, at least on the cookbooks page.