Add oil to heat in pot.
Chop onions and add, along with garlic, chili, cumin, oregano. Let sizzle out.
Optional: add 1lb ground meat of your choice and fry until brown, separating into chunks as it cooks.
Add tomato paste. Let it cook 8 minutes.
Add tomatoes, and bring to a boil.
Let simmer for 10 minutes so that it thickens up real nice.
Meanwhile, open the bean cans, drain the beans, eat some fritos, etc.
Add drained beans, water, and salt.
Simmer for 30-35 minutes.
Before serving, mash up the soup a little with a potato masher, then add smashed fritos and lime juice.
Taste for salt and add more if needed.
Alt: add ¼ cup chipotle pepper in adobo.
Add extra can of beans, any variety.