Preheat your oven to 350°F (175°C).

In a large pot, boil the diced potatoes until tender, about 10-15 minutes. Drain and set aside.

In a skillet, brown the ground beef or turkey over medium heat. Drain any excess fat.

Stir in the taco seasoning and a little water according to package instructions. Mix well.

In a large bowl, combine the cooked potatoes and the meat mixture. Add the sour cream and half of the cheese, mixing until everything is well combined.

Transfer the mixture to a baking dish. Top with the remaining cheese.

Bake in the oven for 20-25 minutes, or until the cheese is melted and bubbly.

Garnish with diced tomatoes and chopped green onions before serving.