Preheat oven to 325º F. Grease 2 muffin trays with nonstick cooking spray.
Carefully slice biscuits in half and press into the inside of the muffin cups.
Spoon heaping tablespoons of chili into the biscuit cups and top with 4-5 slices hot dog and a sprinkling of cheddar cheese.
Brush overhanging biscuit dough with egg wash and bake until golden, 20-25 minutes. Top with onion and chives and serve. (Egg Wash, it's beaten egg either plain, or mixed with milk or water. You brush the wash over your pastry dough before baking so that it browns.)