Heat the oil in a large pot over medium-high for 1-2 minutes and then add the celery, onion, and carrots. Allow the veggies to cook for about 7 minutes, or until the onions begin to brown.
Once the veggies are soft and tender, add the corn, peas, broth, and diced tomatoes. Stir to combine.
Bring the soup to a boil and then reduce the heat to low. Allow the soup to simmer over low heat with a lid on for 15 minutes.