Start the pizza sauce simmering first: Saute the onion and pepper in oil for 3 minutes. Add the garlic and Italian seasoning and saute 1 minute until the onion is soft. Stir in tomatoes and simmer 10-15 minutes, till it thickens to your liking, stirring occasionally. Add the salt, pepper, and sugar to your taste.
Carefully blend the hot sauce until smooth.
To make the burgers: Lightly beat the egg white. Add remaining burger ingredients and mix well. Shape into 6 burgers.
Grill burgers on medium high heat, for 4-5 minutes on each side or until meat is no longer pink.
Top burgers with cheese slices the last 2 minutes of cooking.
Serve burgers on buns topped with cheese and tomato sauce.