Sauté onion and bell pepper in olive oil. Always taste as you go — you can add more seasoning, but you can't take it away! Make sure your pan is properly heated before adding ingredients — you should hear a nice sizzle. Don't overcrowd the pan or things will steam instead of getting that beautiful golden color.
Add garlic and cook 1 minute.
Add all beans (drained and rinsed).
Add both types of tomatoes.
Stir in spices.
Simmer 30-45 minutes, stirring occasionally. Keep an eye on the heat — you want a gentle simmer with small bubbles, not a rolling boil. This helps develop flavor without overcooking.
Season with salt and pepper. Always taste as you go — you can add more seasoning, but you can't take it away!