Brown the ground beef in a skillet over medium heat.

Add the minced onion to the skillet and cook until softened.

Drain any excess fat from the skillet.

In a casserole dish, combine the browned ground beef and onion mixture.

Add the cream of chicken soup to the casserole dish.

Pour water into the casserole dish.

Add the drained vegetables to the casserole dish.

Stir all ingredients together until well combined.

Arrange the frozen tater tots in a single layer on top of the mixture in the casserole dish.

Bake in a preheated oven at 350 degrees Fahrenheit (175 degrees Celsius) for 30-45 minutes, or until the tater tots are golden brown and crispy and the casserole is heated through.