Mix all of the ingredients for the meatballs together well with your hands in a large bowl.
With wet hands, shape into walnut-sized meatballs, then put onto a baking tray or plate.
Switch on the oven at about 100C/210F. Then heat up a tablespoon or so of oil in a big skillet/frying pan and pan-fry the meatballs for about ten minutes, turning regularly, until golden brown and cooked through (you may have to do this in two batches – see note below). Then transfer the meatballs into a dish and pop in the oven to keep hot.
To make the sauce, add a knob of butter to the oil left in the pan you cooked the meatballs in. Then add the flour to the pan and stir into the oil/butter, then gradually add the beef stock, stirring all the time. Let it bubble for a minute or two until thickened (*see note below).
Stir in the berry sauce and mustard and Worcestershire sauce (if using), then take off the heat and stir in the cream. Add the meatballs back into the pan and jiggle around in the sauce until well coated.
Serve the meatballs and sauce over mashed potatoes or with crusty bread and salad. Garnish with herbs and serve a bit of lingonberry/cranberry sauce on the side.
Cooking the meatballs
I sometimes cook just half of the meatball mixture and freeze the rest for another time.If you do this, remember to halve the amount of sauce! If you decide to cook all of the meatballs though, you’ll probably have to fry them in two batches. Just pop the first batch in the oven to keep warm while you cook the second.
The berry sauce
If you can’t find lingonberry sauce/jam, redcurrant or cranberry sauce/jam are good substitutes.
Making the gravy
*This is by no means essential, but I pour my sauce into a mini blender to make it super smooth before pouring it back into the pan and adding the meatballs to it.