Prepare Crostini: Toss cubed Italian bread with 3 tablespoons olive oil and 1/2 teaspoon coarsely cracked pepper in a bowl.

Spread bread mixture on a rimmed baking sheet and bake in a 400°F (200°C) oven for 6-8 minutes, tossing once, until golden and crisp. Set aside.

Cook pasta separately according to package directions. Drain and set aside.

Prepare Soup Base: In a large pot or Dutch oven, sauté 1 chopped onion, 3 sliced celery stalks, 3 sliced carrots, 3 minced garlic cloves, 2 bay leaves, 1 teaspoon salt, and 1 teaspoon pepper in 1 tablespoon olive oil for 5-8 minutes, or until vegetables are softened.

Transfer the sautéed vegetables to a slow cooker.

Add Tomato and Beans: Stir in 5 1/2 ounces tomato paste, 1 lb smoked ham hock, parmesan cheese rind (optional), cubed potato, rinsed and drained red kidney beans, rinsed and drained white kidney beans, and 8 cups water.

Slow Cook: Cover the slow cooker and cook on low for 6-8 hours, or until the ham can be easily pulled off the bone.

Remove and Discard: Remove and discard the bay leaves and parmesan rind.

Add Vegetables: Increase the heat to high. Stir in 1 diced red pepper and 1 small zucchini.

Cook for 20 minutes, covered, until the vegetables are tender.

Add Pasta: Stir in the cooked pasta.

Serve hot, topped with crostini.