01 -
Heat olive oil over medium heat in a large pot. Add diced onion and cook until softened and translucent, about 4 to 5 minutes.
02 -
Add ground beef to the onions, season with taco seasoning, and cook until beef is browned and crumbled, about 8 to 10 minutes.
03 -
Transfer cooked beef and onions from the pot, leaving behind drippings for added flavor.
04 -
Melt butter in the same pot over medium heat. Add flour and whisk continuously for 1 to 2 minutes until the mixture turns lightly golden.
05 -
Slowly whisk milk into the roux until smooth and slightly thickened, about 2 to 3 minutes. Stir in undrained Rotel. Gradually add shredded cheddar cheese, stirring until fully melted and the sauce is creamy. Mix in sour cream, several dashes of hot sauce, and additional taco seasoning to taste.
06 -
Return the cooked beef and onions to the cheese sauce. Stir thoroughly to combine. Reduce heat and let simmer on low for 10 minutes, allowing flavors to blend and sauce to thicken.
07 -
Preheat oven to 350°F. Arrange taco shells on a baking sheet and heat for 5 minutes until crisp.
08 -
Generously spoon the cheesy beef mixture into each taco shell, letting it overflow slightly for rich presentation. Serve hot, optionally paired with Spanish rice.