- Preheat your oven to 350°F (175°C). 
- In a skillet, cook the ground beef over medium heat until browned. Drain the fat. 
- Add the taco seasoning to the beef and stir to combine. 
- In a mixing bowl, combine the sour cream, mayonnaise, and half of the shredded cheese. 
- In a baking dish, layer the biscuits on the bottom. 
- Spread the beef mixture over the biscuits. 
- Top with the sour cream mixture, then add the chopped onions and diced tomatoes with green chilies. 
- Sprinkle the remaining shredded cheese on top. 
- Bake in the preheated oven for 30 minutes, or until the cheese is melted and bubbly.