Sauteed Onions And Peppers (Barefoot Contessa) Ina Garten - cooking recipe

Ingredients

6 large yellow onions
1/4 cup olive oil
2 red bell peppers, julienned
2 yellow bell peppers, julienned
3 garlic cloves, minced
1 lb button mushroom, sliced thin
1/4 cup sherry wine vinegar
1 tablespoon tomato puree
1/2 teaspoon red pepper flakes, to taste
1 teaspoon kosher salt
1/2 teaspoon fresh ground black pepper

Preparation

Cut the onions in half and then slice into 1/8 \" thick half-rounds (About 10 cups of onions).
Heat the olive oil in a large saute pan over medium heat.
Add onions and mushrooms and saute for 15-20 minutes. Add the peppers, garlic, vinegar, tomato puree, pepper flakes, salt and pepper and continue cooking an additional 10 minutes.