Use hot sausage for a spicier dish.
Melt butter in Dutch oven and brown sausage over low heat. Drain off fat. Sprinkle with flour and stir until blended. Add stock, tomatoes, basil, and oregano. Bring to a boil, reduce heat, and simmer 30 minutes, partially covered. Add zucchini and pasta and simmer 10 minutes longer or until tender. Season with salt and pepper. (If preferred, cook pasta in separate saucepan, add to stew, and stir.)