In a large skillet sauté onion, leek in olive oil until very soft and starting to brown.

While they cook, make the meatballs:

In medium bowl combine egg, bread crumbs, mustard, ketchup, Worcestershire and garlic. Mix well.

Add beef and mix well – hands work best (and fastest).

Form into small meatballs, about 1? (2.5cm) in diameter. Set aside.

When onion/ leek are ready add beef stock, mustard, ketchup and Worcestershire sauce to skillet and stir well. Heat to simmering. 

When simmering add the meatballs, being careful that they don’t touch.  Cover and continue to simmer until done, stirring and turning the meatballs once or twice, about 15 minutes.

Uncover and increase heat."recipe from recipes and cooking guide ".

Add the cornstarch mixture, stirring until thickened.

Serve over noodles, mashed potatoes, rice….