Mix dried onion with water in a small bowl and let stand for five minutes.
Combine ground beef, flour, chili powder, paprika and salt. Mix well. Add onions and water. Mix again. In a skillet, cook beef mixture until browned. Stir often while cooking so no large chunks form; it should be more like a paste.
Remove from heat and keep warm. In a deep-fryer (or you can use a skillet) deep fry the bread for 30 seconds. Let drain on absorbent towels. Build Chalupas starting with meat, then sour cream, lettuce cheese, and tomatoes in that order. Top with hot sauce or salsa if desired.