
Heat a large nonstick skillet over medium-high heat. Add in olive oil, sliced bell peppers and sliced red and yellow onions.
Add in the salt, red pepper flakes, black pepper and dried oregano.
Stir to coat the vegetables with the olive oil and seasonings. Cook, stirring occasionally, for 15-17 minutes until the peppers and onions have softened and started to caramelize.
Add in the red wine vinegar and minced garlic. Mix together and cook for 1 more minute. Taste and season with more salt if necessary.
Remove the peppers and onions from the heat and serve.