In a large skillet, heat the olive oil and sauté the onions until translucent. Add the beef and the parsley and cook for a couple of minutes. Reserve.

In a small saucepan, melt the butter and add the flour slowly to make a roux.

Gradually add the broth, making sure the roux is absorbing the liquid. Stir constantly until it thickens.

Add the meat mixture and cook for a little longer until you have a very thick gravy. Stir in the salt, pepper and nutmeg.

Transfer the gravy to a shallow container and refrigerate for 2 hours.

Once the gravy is chilled and solidified, roll the bitterballen (1 inch diameter).

Roll the bitterballen in the all purpose flour, then the egg wash and finally the breadcrubs. Proceed until you've breaded all bitterballen.

Bring your bitterballen to the freezer for 30 minutes before frying.

In a small saucepan, heat enough oil to cover the balls.

Fry your bitterballen, 5 at a time, until golden brown.

Set your bitterballen on a plate covered in paper towels to absorb the excess oil.

Serve the bitterballen hot, with some grainy mustard on the side.