Preheat the oven to 325°F. On the stovetop, melt 3 tablespoons of butter over medium-high heat.In a 6 quart dutch oven or similar oven safe pot.
In a small bowl, whisk together flour with ¼ teaspoon salt, ¼ teaspoon paprika and ¼ teaspoon black pepper. Dust chicken breasts on all sides with seasoned flour.
Brown chicken in butter for 1 minute on both sides. Arrange in dutch oven or buttered baking dish. Top with onion and a light dusting of paprika.
In a small mixing bowl, whisk together, soup, dissolved soup base, half and half, poultry seasoning, garlic powder, tarragon and black pepper. Pour the over the chicken and onions.
Bake covered for 50-60 minutes. Remove lid and test the chicken for doneness. Time may vary adjust cooking time depending on the thickness of chicken breasts used. Remove chicken to a platter to rest for 5 minutes. Mix gravy well. (See Cook's note for how to thicken graqvy with cornstarch, if desired.)
Serve smothered chicken and gravy garnished with parsley. Serve with cornbread dressing, cooked rice, cooked pasta, mashed potatoes or any of your favorite Southern side dishes.