Heat oil in a large skillet or pan over low heat. Add onions and cook and stir until they slightly translucent (2-3 minutes).
2. Adding vinegar
Pour in vinegar and season with pepper, and salt to taste.Stir until the onions turn a bright color (2 minutes). It can go from bright pink to bright purple depending on the onion you used.
3. Serving
Remove from the heat.Use this to garnish the dishes in the serving suggestions above the recipe.