Prepare the Pie Crust: In a large bowl, mix the flour and salt. Add the cold butter cubes and use a pastry cutter or your fingers to blend until the mixture resembles coarse crumbs. Gradually add ice water, a tablespoon at a time, mixing until the dough just comes together. Form the dough into a disk, wrap it in plastic wrap, and refrigerate for at least 30 minutes.

Cook the Filling: In a large skillet, cook the ground beef over medium heat until browned. Drain excess fat. Add the onion and bell pepper to the skillet and sauté until softened, about 5 minutes. Stir in the diced tomatoes, green chilies, garlic powder, cumin, chili powder, paprika, salt, and black pepper. Pour in the beef broth and simmer for 10 minutes, allowing the mixture to thicken slightly. Remove from heat and stir in the sour cream, cheddar cheese, and Monterey Jack cheese until combined.

Assemble the Pie: Preheat your oven to 375°F (190°C). Roll out the chilled pie crust on a floured surface and line a 9-inch (23 cm) pie dish with it. Pour the beef mixture into the crust, spreading it evenly.

Bake: Roll out the remaining dough to cover the top, or create a lattice pattern. Seal the edges and cut slits into the top crust to allow steam to escape. Bake for 30–35 minutes, or until the crust is golden brown.

Serve: Let the pie cool for 5–10 minutes before slicing. Serve warm, garnished with additional sour cream or chopped cilantro if desired.