White Bean, Italian Sausage, and Fennel Soup

1 pound Italian precooked sausage, sliced
3 tablespoons olive oil, divided
1 large yellow onion, chopped
2 stalks celery, chopped
1 medium carrot, sliced
1 small fennel bulb, sliced
3 garlic cloves, chopped fine
1/2 teaspoon red pepper flakes
1 bay leaf
1 teaspoon chopped fresh rosemary
1/4 cup dry white wine
6 cups chicken broth
2 15-oz. cans cannellini beans, drained, rinsed
1 15-oz. can fire-roasted diced tomatoes
Sea salt and black pepper, to taste

1. Heat a large soup pot over medium-high heat. Add 2 tablespoons olive oil and sausage, and cook, stirring, until sausage is lightly browned, about 8 minutes. Remove sausage and set aside.
2. Add the remaining tablespoon olive oil, onion, celery, carrot, fennel, salt, bay leaf, rosemary, and red pepper to the pot. Saute until vegetables are softened, about 8 minutes. Add the garlic and cook 1 minute.
3. Deglaze the pot with the white wine and scrape up any browned bits. Stir in broth, beans, and tomatoes and bring to a boil. Reduce heat to medium-low and simmer 15 minutes or until vegetables are tender. Season with salt and pepper and add the cooked sausage; heat through, 1 or 2 minutes. Remove bay leaf before serving. Serve garnished with rosemary sprigs.