Can you recommend an appropriate source of protein for a vegetarian diet?

Many: Whole grains are a great source of protein, but the one with the highest protein content is quinoa. All beans, lentils, & peas, tofu & soy products, edamame, tvp and tempeh. Nuts, including peanuts, cashews, almonds and walnuts all contain protein, as do seeds like sesame seeds and sunflower seeds. Store-bought meat substitute products & seitan are rich in protein, as are protein shakes.