For a richer flavor, consider sautéing the vegetables in a skillet with the olive oil before adding them to the slow cooker. If you don't have ditalini pasta, you can substitute another small pasta shape, such as elbow macaroni or orzo. Feel free to add other vegetables to your minestrone, such as spinach, kale, or bell peppers. For a heartier soup, add a can of cannellini beans along with the chickpeas. Homemade vegetable stock will elevate the flavor of this soup significantly. Adjust the amount of pesto to your liking. Some prefer a more pronounced pesto flavor. This minestrone tastes even better the next day, as the flavors have time to meld.