In a medium saucepan, heat ½ cup of olive oil over low to medium-low heat.
Add the sliced onion and bell peppers, stirring to coat them in the oil.
Mix in the minced garlic, bay leaves, salt, and pepper.
Finally, pour in ⅓ cup of white vinegar, stir everything together, and cover the pan with a lid.
Let the escabeche cook for about 10 minutes, stirring occasionally. The vegetables should be softened but still vibrant.