Denver Mile-High Taco Burger

1 pound lean ground beef
1 (1 ounce) envelope taco seasoning mix
Sliced Monterey jack cheese with hot peppers (pepper jack)
4 sandwich buns
Shredded lettuce
Sliced tomato
Mustard, to taste
Catsup, to taste
Mayonnaise, to taste
Tortilla chips

Mix together ground beef and seasoning mix in a medium bowl. Form 4 patties. Grill to desired doneness. Place cheese on each burger and heat briefly to soften cheese. Serve burgers in buns with lettuce, tomato, condiments and chips.