Pat mushrooms dry with paper towels. Heat 1 tablespoon butter in a heavy-bottomed pot over high heat. Add 2 cups of mushrooms and cook without stirring for 5 minutes until golden brown. Transfer to a plate and repeat with remaining mushrooms.
1.5 lbs cremini mushrooms, 2 tbsp butter
Lower heat to medium. Add remaining butter to the pot. Cook pearl onions for 5 minutes until they start to brown. Stir in minced garlic and cook for 30 seconds. Add tomato paste and cook 2 minutes until it darkens.
1 cup pearl onions, 4 cloves garlic, 2 tbsp tomato paste, 2 tbsp butter
Pour in red wine and scrape the bottom of the pot with a wooden spoon to lift browned bits. Simmer for about 3 minutes until the wine reduces by half.
1 cup dry red wine
Return browned mushrooms to the pot. Add carrots, vegetable broth, thyme sprigs, and bay leaves. Bring to a simmer, then reduce heat to low and cover the pot partially. Cook for 40 minutes until carrots are fork-tender and the sauce thickens.
1.5 lbs cremini mushrooms, 3 medium carrots, 3 sprigs fresh thyme, 2 leaves bay leaves, 2 cups vegetable broth
Remove thyme sprigs and bay leaves. Taste and adjust seasoning with salt and pepper as desired. Remove pot from heat and let stew rest for 10 minutes before serving.
3 sprigs fresh thyme, 2 leaves bay leaves
