Heat the oil in a saute pan over medium heat.
Add the onion to the pan and cook, stirring occasionally, until the onion softens, about 5 minutes.
Stir in the bell peppers and garlic and continue to cook, stirring occasionally, for about 5 more minutes.
Stir in the tomatoes, cayenne, ½ tsp salt, and ¼ tsp black pepper and continue to cook, stirring occasionally, for about 15 minutes.
Take off the heat and season with salt & freshly ground black pepper to taste.
