Preheat oven to 350 F. Heat olive oil in a large saucepan over medium heat. Cook onions, carrots and minced garlic until the vegetables are softened.
Mix in soup, milk, frozen peas and cooked chicken. Cook until it is heated through. Pour the mixture out into a greased baking dish.
Top with frozen tater tots. Bake for 30 minutes. Top with shredded cheddar cheese and bake for another 15-20 minutes.