Place brie in a shallow ovenproof casserole or pan 2 inches wider than the cheese. Spoon salsa about 1/2 inch deep around cheese. Dust cheese with ground New Mexico chili or chili powder (use a stencil if desired).
Bake in a 400° oven until melted in center, 8 to 10 minutes. (Or heat in a microwave oven at full power, 100%, for 4 to 6 minutes.) Keep hot on an electric warming tray or over a candle warmer to serve. Offer tortilla chips to spoon cheese and salsa onto.