Seared Sausages with Hearty Veg and Polenta

Name: Seared Sausages with Hearty Veg and Polenta
Ingredients: 1 bulb fennel; 2 small red onions; 18.25 ounces (540 milliliters) canned white kidney beans, drained and rinsed; 6 garlic cloves, skin on; Olive oil; 1/2 teaspoon vegetable or chicken bouillon powder, optional; Kosher salt and freshly ground black pepper; 4 cups (1 liter) chicken broth; 1 cup (5.25 ounces/150 grams) polenta or yellow cornmeal; 4 Italian sausages, mild or spicy; 1 bunch rapini or Tuscan kale, ribs removed; 1/2 lemon, zested and juiced; 1/2 teaspoon crushed red pepper flakes; 1/2 cup (1.4 ounces/40 grams) finely grated Parmigiano-Reggiano, for serving, optional