mix salsa, barbecue sauce, jalapeno pepper liquid, dry mustard, and salt in a large bowl. Add the meat; marinate for several hours.
Heat grill. A charcoal grill stocked with oak charcoal is best, but a gas grill works well too. Wipe excess marinade from the meat. Apply meat seasoning.
Grill steak over medium until cooked to taste, usually 25 to 30 minutes. For medium rare the temperature should be 145°. Let meat rest for 5 to 10 minutes. Slice very thin. Serve with beans and toasted bread. 360 calories per serving. Serves four