Step 1: Prepare the Vegetables

1. Wash and dice the onion, carrots, celery, zucchini, and green beans. Mince the garlic.

Step 2: Assemble the Slow Cooker

1. Add the diced vegetables, canned tomatoes (with juice), kidney beans, cannellini beans, vegetable broth, and water to the slow cooker.
2. Sprinkle in the oregano, basil, thyme, crushed red pepper flakes (if using), salt, and black pepper. Stir well to combine.

Step 3: Cook the Soup

1. Cover the slow cooker with the lid and cook on low for 6-8 hours or high for 3-4 hours.
2. During the cooking process, the vegetables will become tender, and the flavors will meld together.

Step 4: Add the Pasta and Greens

1. About 30 minutes before the cooking time is up, stir in the pasta and chopped spinach or kale.
2. Replace the lid and cook until the pasta is tender and the greens are wilted.

Step 5: Garnish and Serve

1. Taste the soup and adjust seasoning with additional salt or pepper if needed.
2. Ladle the soup into bowls and garnish with chopped parsley and grated Parmesan cheese, if desired. Serve with crusty bread or crackers for a complete meal.