Gozzo/Gotsu 

(South Indian Tomato & Onion Sauce)

This is a South Indian sauce with mustard seeds, onions, and tomatoes. It's nice with a milder main dish like Khichdi (rice & dal) or Upma (like savory cream of wheat). I think the first time, I made it to go with Ven Pongal (rice and dal). I know my South Indian friend approved of the combination! (The recipe is from Julie Sahni's Classic Indian Vegetarian and Grain Cooking.)