1. Place a 12-inch skillet over medium-high heat, and add the olive oil and the butter. When the butter begins to foam, add the diced onions and sauté until translucent, 3 to 4 minutes. Add the garlic and cook until fragrant, about 30 seconds. Add the mushrooms and cook, stirring often, until they have released most of their liquid, about 10 minutes.
2. Add the thyme, oregano, diced tomatoes, tomato paste, and stock, and bring to a boil. Reduce the heat to a simmer and cook, stirring occasionally, until the liquid has reduced and the ragout has thickened, about 20 minutes. Season with the salt and pepper, and stir in the parsley.
3. Divide the Creamy Polenta among four to six shallow bowls, and top with the mushroom ragout. Garnish with the Parmesan and chives, and serve hot.
Yield: 4 to 6 servings