My new boyfriend is a vegetarian, and always plans his meals by what makes full proteins. I feel too stupid to ask him, but I really want to know. I know I don't eat meat on a daily basis, so even though I'm not a vegetarian myself, it still sounds like good stuff to know.
Peanut Butter and Bread (grains and peanuts) although too much of it of course could be high in fat. Rice and lentils. Hummus (sesame paste, lemon juice and chick peas) and pitta bread. High protein meal replacement formulas. If milk is included it is a good source of complete protein, probably best absorbed if taken in a fermented state like kefir or good quality yochurt. Cheese, but that could also be high in fat.
Deanhills is pretty much spot on there. I wouldn't feel stupid to ask him though - if anything it shows that you care! If you really don't want to ask him directly, you could just find out what some of his favourite foods are.