1 In a large skillet, heat oil and butter over medium heat.2 Add onion; cook, stirring often, until soft, about 5 minutes.3 Add mushrooms; season generously with salt and pepper. Cover and cook until mushrooms release their juices, about 10 minutes.4 Add the minced garlic. Uncover pan; raise heat to high.5 Cook, stirring often, until liquid has evaporated and mushrooms are brown, 2 to 3 minutes.6 Add wine, rosemary, and tomatoes.7 Simmer until sauce has thickened, 10 to 15 minutes8 Meanwhile, make the polenta. In a large saucepan over high heat, bring stock and milk to a boil.9 Reduce heat to medium, and very gradually, add cornmeal in a thin stream, whisking constantly until smooth.10 Remove from heat and stir in reserved rosemary, cheese, butter, and walnuts. Salt and pepper to taste.

Source: California Walnut Board