In a large bowl mix together your cheese, chilies, jalapeños, and onion.
Brush one side of each tortilla with melted butter and salt. Place butter side down on a baking sheet and scoop cheese mix into the center of each tortilla.
Place in oven and bake for about 5 to 10 minutes, long enough fo the cheese to get nice and melted.
Allow to col a little bit and fold in half, and serve.