Peel the onions and cut into quarters, and then into fine sticks.
Add olive oil to large skillet and when hot add peeled garlic cloves and onion sticks and sautè until tender, stirring occasionally, about 15 minutes.
Meanwhile wash bell peppers, discard seeds, cut into sticks and toss in the skillet.
Blend well, cover and simmer about 15 minutes. Add peeled tomatoes and salt and pepper to taste and cook 15 minutes.