1. Cut baguette in half horizontally.
2. In a bowl, mix shredded cheese, chilies, onion, sour cream, garlic, and 1/4 teaspoon paprika.
3. Spread mixture evenly over cut sides of baguette; dust lightly with more paprika. Set, cheese mixture up, on a 14- by 17-inch baking sheet.
4. Broil 4 inches from heat until topping is puffy and lightly browned, about 6 minutes. For appetizers, cut into 1 1/4- to 1 1/2-inch-long pieces; to serve as a bread, cut into 3- to 4-inch sections. Serve warm.