Heat oil in large high-sided, oven-proof skillet over medium heat Add sliced onion, bell peppers, asparagus, and carrots and cook 3 to 5 minutes, until crisp-tender. Stir in tarragon and vermouth cook 2 to 3 minutes. Add spinach (or dandelion greens) and milk and sour cream and simmer 2 minutes. Add more milk, if needed, to make sure the vegetables are submerged. Season, to taste, with salt and black pepper. Sprinkle Parmesan cheese over the top. Place pan under broiler and broil until golden brown. Serve mixture over rice.
Chef's Note: You can clean and cut all vegetables and reserve in refrigerator, to be used when cooking fricassee.