cook onions in hot
oil until crispy and
brown, add tomatoes

source, 4 servings
1/2 lb white beans, soaked overnight in 2 inches water, simmered until tender, drained, salted; 3 big sliced seeded tomatoes, 1 big sliced red onion, 1/4 c canola oil
brown onion in oil, add tomatoes, cook 5 minutes; add beans & 1 c liquid, cook down