Heat olive oil in a large pot (4-quart or larger) over medium heat. Add onion, carrots, celery, and garlic. Saute for about 5 minutes, stirring occasionally, until vegetables soften and become fragrant. Onion should be translucent.
Stir in diced tomatoes with all their juices, vegetable broth, rinsed cannellini beans, pasta, kale, Italian seasoning, salt, and pepper. Distribute ingredients evenly throughout the pot.
Bring to a boil over high heat, then reduce heat to medium-low. Simmer uncovered for 20 minutes, or until pasta is tender and vegetables are soft. Check pasta at 18 minutes to avoid overcooking. Taste and adjust seasoning as needed.
Notes
Always rinse cannellini beans to remove excess sodium and prevent cloudy broth.
Use small pasta like ditalini or small shells for best results. Pasta continues cooking after removing from heat, so don’t overcook.
Can substitute kale with spinach or Swiss chard. Other beans like Great Northern or kidney beans also work well.
Soup tastes even better the next day as flavors deepen. Perfect for meal prep.
If freezing, cook pasta separately and add fresh when reheating to maintain better texture.