Frikadeller is served everywhere as a hearty meal or as a tasty and well loved meal when friends get together. Danish meatballs may just be the common food that binds Denmark together as a country! Much better than those Swedish ones at IKEA.
Mix meat and onions together. Add egg and mix again. Add flour and remaining ingredients.
Using a melon baller or small spoon, form into melon ball sized balls. Place on waxed paper and slightly squish each ball so it is flattened slightly.
Melt butter in frying pan and cook balls for 10 min on each side at medium heat. While frying the balls on the last side to be browned, make the gravy.
Melt butter over low heat in a medium saucepan. Add flour and stir until smooth. Add half of the meat stock slowly while constantly stirring. Raise heat to high and bring to a boil. Add rest of the stock along with the vinegar and boil for 3 minutes, while constantly stirring. Add pepper and salt. Add sherry and dill, if using, at the very end, just before removing from heat. Remove from heat, allow gravy to cool for 4-5 minutes, while stirring constantly.