May 17, 2020 · How to make Tater Tot Casserole in the slow cooker: Brown hamburger and onion in a skillet and drain the fat. Add cream of mushroom soup, milk, salt and pepper to the beef. Stir. Set aside. Add half a bag of frozen tater tots to the bottom of the slow cooker … Sep 08, 2021 · Step by Step Directions. Step 1 – In a small bowl, add the water and beef bouillon cubes. Microwave until hot, about 30 seconds. Step 2 – Dissolve the beef bouillon into the water, do this by squishing the cubes with the back of a spoon.. Step 3 – Add the soy sauce, Worcestershire sauce, brown sugar, seasonings, and cornstarch. (Add red pepper flakes if you want your sauce spicy).