Winter Portabella Mushroom Stew

• 4 tablespoons olive oil
• 1 large onion, cut into 1/2-inch dice
• 2 teaspoons chopped fresh rosemary
• 8 ounces portabella mushrooms, sliced 1/2-inch thick, gills removed
• 1 lb large white mushroom, thickly sliced
• 1 (14 1/2 ounce) can diced tomatoes
• 3 tablespoons tomato paste
• 2 garlic cloves, minced
• 1 teaspoon sherry wine vinegar
• 2 tablespoons butter (optional)
• salt & fresh ground pepper, to taste
• 2 pinches red pepper flakes

1. Heat 1 tablespoon oil in large nonstick skillet over medium heat.
2. Add onions and rosemary and cook stirring occasionally, until lightly browned, about 12 minutes; remove to a bowl.
3. Return the pan to the stove and add half the remaining oil.
4. When it's hot, add the portabella mushrooms and saute until nicely browned, about 5 minutes.
5. Add portabellas to the onion mixture and repeat sauteing with the remaining oil and the white mushrooms.
6. Return everything to the pan and add the tomatoes, tomato paste, garlic, 1-1/2 cups water and vinegar.
7. Simmer gently for 12 to 15 minutes, then swirl in the butter.
8. Season with salt, pepper and red pepper flakes.

olive oil, onion, fresh rosemary, portabella mushrooms, white mushroom, tomatoes, tomato paste, garlic, sherry wine vinegar, butter, salt, red pepper

Taken from www.food.com/recipe/winter-portabella-mushroom-stew-138154 (may not work)