To prepare Avocado Relish: Cut avocado lengthwise around the pit; twist halves to separate; strike pit with a knife blade and pull to remove; gently scoop out flesh with a spoon. Dice avocado (makes about 1 cup). In a small bowl, combine bell pepper, onion, vinegar, sugar, salt and ground red pepper; gently stir in avocado. Meanwhile, preheat a countertop or charcoal grill; cook hot dogs until hot and lightly browned, about 5 minutes (alternatively, cook over medium heat in a large skillet, turning once). Spread cut sides of buns with mustard. Place hot dogs in buns; spoon Avocado Relish on top. Serve with tortilla chips, if desired.