1. Prepare Your Aromatics: In a large pot or Dutch oven, heat the olive oil over medium heat. Add the chopped yellow onion and cook until softened and translucent, about 5-7 minutes. If making the garlic soup, add the minced garlic during the last minute of cooking the onion and stir until fragrant. For the French-style soup, add the sliced leeks with the onion and cook until tender.

2. Build the Flavor Base: Pour in the vegetable or chicken broth. Stir in the dried thyme and black pepper. Bring the mixture to a gentle simmer.

3. Add Your Main Ingredients: If using, stir in the cooked white beans. If you’re including small pasta, add it now. Cook according to package directions, usually about 8-10 minutes, or until the pasta is al dente. The pasta should be tender but still have a slight bite.

4. Season and Taste: Once the beans are heated through and the pasta is cooked (if using), taste the soup. Add salt as needed, starting with a quarter teaspoon and adding more until the flavor is balanced and pleasing. Remember that broth can vary in saltiness, so always taste before adding too much.

5. Finish with Freshness: Remove the pot from the heat. Stir in the fresh chopped parsley just before serving. This adds a vibrant color and a fresh, herbaceous note.

6. Serve Warm: Ladle the hot soup into bowls. Serve immediately with a side of crusty bread or a sprinkle of croutons for added texture.