Preheat oven to 350ºF. Lightly spray an 8×8-inch or 11×7-inch pan with cooking spray.

Cook ground beef in a skillet over medium heat until no longer pink. Drain fat. Add taco seasoning, water, and diced tomatoes and green chiles. Simmer for 5 minutes.

Spread taco meat in the bottom of the prepared pan. Top with shredded cheese.

Whisk together eggs, milk/heavy cream, and sour cream. Pour on top of the beef mixture.

Bake, uncovered, for 30 to 35 minutes.