In a skillet, melt the butter over medium heat.
Add the diced onion and jalapeno, sauté until softened.
Add the ground chorizo, cook until browned and cooked through.
Reduce heat to low, add the grated Queso Asadero and Pepper Jack cheese to the skillet.
Stir until cheese is melted and bubbly.
Garnish with fresh cilantro and tomatoes.
Serve hot with tortilla chips or tortillas.