For crust, grease a 10 inch pie pan. Cook vermicelli or spaghetti and drain. In a large bowl, blend together egg and mustard. Add cooked pasta and toss to coat evenly. Spoon pasta mixture into pie plate and push up sides of pan to form a crust.
Fry ground beef in a skillet, add onion and salt. Cook on medium heat until beef is cooked through. Drain off fat and return to skillet.
Stir in bacon and tomato sauce. Spoon beef mixture into pasta-lined pan, pushing to edge and almost covering spaghetti sides. Top with 1/2 cup cheddar cheese.
Bake at 350 degrees for 30 minutes. Top with pickle slices, and sprinkle with remaining 1/2 cup cheese. Bake another 10 to 15 minutes, until thoroughly heated and cheese is melted.