Add oil to hot pan. Add sausages and brown on all sides. Remove sausages to plate.
Add onion, fennel, and garlic to pan. Saute until softened. Deglaze with white wine and cook until reduced by half. Pour chicken broth and chicken bouillon into pan. Add sausages back to pan with any juice on plate.
Cover and simmer 20 minutes. Remove sausages and slice into rounds. Taste sauce and adjust seasonings.
Add sliced sausages back to sauce. Serve over pasta and garnish with basil.