Sauté diced sausage in a large sauté pan; drain fat and set aside. Finely chop shallot, garlic, and fennel and sauté with white wine and 1/4 cup butter. Add to cooked sausage and set aside. Finely chop mushrooms and sauté with remaining 1/4 cup butter and 4-6 oz of stock until desired texture (about 12 minutes), adjusting liquid as needed. Add vegetable and sausage mixture and let cool slightly before folding in cheeses. Serve on crostini and pair with Pinot Noir.