Preheat the oven to 350°F (175°C).
In a skillet over medium heat, cook ground beef until browned. Drain excess fat.
Add taco seasoning and water. Simmer for 5 minutes, stirring occasionally.
Warm the refried beans in a saucepan or microwave until soft and spreadable.
Spread a layer of refried beans on each tortilla, add a layer of seasoned beef, and sprinkle with cheddar cheese.
Roll up each tortilla and place seam-side down in a baking dish.
Pour enchilada sauce over the enchiritos and sprinkle with more cheddar cheese.
Bake uncovered for 15–20 minutes, until the cheese is melted and bubbly.
Top with diced onions and a dollop of sour cream, if desired, and serve hot.