Mix the ground beef and chorizo together. Divide into four equal sections and form into patties.
Cook burger patties in a skillet or on the grill.
For the Queso Blanco
Add the milk, jalapeno, cumin, salt, pepper, and chili powder to a medium saucepan over medium-low heat.
When the mixture is heated and almost starting to simmer, add the cheese.
Continue to melt the cheese stirring occasionally to keep it from burning or sticking. Once melted, stir in butter {if using non-dairy milk} and keep warm until ready to use.
To Assemble
Slice and toast the buns. Top with lettuce and tomato, then the burger patty and onion slices.
Pour the melted queso blanco over the top and serve with your choice of side.