Preheat oven to 350 degrees F. Butter or spray a 9 x 9 inch casserole dish with non-stick spray; set aside. Whisk together the cream soup and milk until well blended; set aside.
Add olive oil to a large skillet and saute the onion and bell pepper until softened but not browned, about 5 minutes. Stir in the ground beef and brown; drain if needed and return to the skillet. Add the minced garlic, cook and stir another minute. Add in the chopped smoked sausage and cook about 3 minutes. Stir in the basil, thyme, Cajun seasoning; taste and add salt and pepper only as needed. Transfer meat mixture to the prepared casserole dish and sprinkle with 1/4 cup of the cheddar cheese. Evenly pour the soup mixture over the top. Arrange the tater tots on top and bake uncovered at 350 for 45 minutes to 1 hour, or until potatoes are nicely browned and crisp. Sprinkle the remaining 1/4 cup of shredded cheese on top and return to the oven just until cheese is melted.
Serve immediately with a green vegetable or a mixed garden salad.