In large bowl, mix pork sausage, onion and salt. Divide the mixture into 4 equal patties.
Roll each hard-cooked egg in flour to coat; place on sausage patty and shape sausage around egg. Dip each into beaten egg; coat with panko bread crumbs to cover completely. Place on ungreased cookie sheet.
Bake 35 minutes or until sausage is thoroughly cooked and no longer pink near egg.