Pasta with Brussels Sprouts and Bacon

INGREDIENTS

• 6 ounces bacon (about 7 slices), cut into 3/4-inch pieces
• Up to 1/4 cup extra-virgin olive oil
• 2 large garlic cloves, minced
• 4 large shallots, cut into thin rounds
• 1 1/4 pounds brussels sprouts, trimmed and halved (quartered if large)
• 1 1/4 cups homemade or low-sodium store-bought chicken stock
• Coarse salt and freshly ground pepper
• 12 ounces rigatoni pasta
• 1/2 cup freshly grated Parmesan cheese, plus more for serving
• 1/3 cup coarsely chopped fresh sage leaves, about 20 leaves