128-oz.package frozen chopped spinach thawed and squeezed dry
2 cupsSwiss cheese, shredded (8 ounces)
Preheat oven to 375ºF.
Melt 1 Tablespoon butter and olive oil in a Dutch oven. Add the chicken; and cook over medium heat until white on all sides, about 5 minutes. Remove chicken from pan; set aside. Add sliced mushrooms to Dutch oven. Increase heat to high and cook, stirring constantly until browned and all liquid has evaporated, 2 to 3 minutes. Remove mushrooms from pan; set aside.
Add remaining 3 Tablespoons butter to Dutch oven set over medium heat. When the butter is melted, add onion; sauté over medium heat 5 minutes. Add minced garlic; cook for about 30 seconds until fragrant. Add flour and stir to combine. Cook over medium heat for 1 to 2 minutes. Add milk and Vermouth. Cook, stirring constantly until mixture has thickened. Add salt, pepper, thyme, sage and grated Parmesan cheese. Continue to cook over medium heat until Parmesan cheese is melted. Add spinach; stir to combine. Return chicken and mushrooms to spinach mixture; cook over medium heat until heated through. Correct the seasonings.
Pour the spinach mixture in a 2½ quart casserole dish. Top with shredded Swiss cheese. Bake at 375ºF for 20 minutes to 30 minutes, or until bubbly and lightly browned. Yield: 6 servings.