2 tablespoons olive oil
2 tablespoons butter, softened
2 pounds portobello mushrooms, in 1/4-inch slices (save the stems for another use) (you can use cremini instead, as well)
1/2 carrot, finely diced
1 small yellow onion, finely diced
2 cloves garlic, minced
1 cup full-bodied red wine
2 cups beef or vegetable broth (beef broth is traditional but vegetable to make it vegetarian; it works with either)
2 tablespoons tomato paste
1 teaspoon fresh thyme leaves (1/2 teaspoon dried)
1 1/2 tablespoons all-purpose flour
1 cup pearl onions, peeled (thawed if frozen)
Egg noodles, for serving
Sour cream and chopped chives or parsley, for garnish (optional)

Heat the one tablespoon of the olive oil and one tablespoon of butter in a medium Dutch oven or heavy sauce pan over high heat. Sear the mushrooms until they begin to darken, but not yet release any liquid — about three or four minutes. Remove them from pan.