Place oil in a large pot and heat to medium-high. Add onion, carrots, and celery. Sauté, stirring occasionally, 8–10 minutes or until vegetables are tender. Add garlic and stir until fragrant, about 30 seconds. Add thyme, Italian seasoning, and salt and pepper. (I add ½ teaspoon of each, but add to taste. You may want to hold off adding salt until the end; saltiness varies depending on the broth or bouillon you use.)
Stir in water and chicken bouillon or low-sodium chicken broth and undrained diced tomatoes. Bring soup to a boil over high heat.
Once boiling, stir in pasta and cook, stirring occasionally, 6–7 minutes or until pasta is tender. Stir in drained and rinsed beans, corn, and peas just to warm through. Remove from heat, taste/adjust seasonings, and ladle soup into bowls. Add a generous spoonful of fresh basil pesto to each bowl. Stir in the pesto and enjoy!
