1 rounded tablespoon, or a little more, of the jam or jelly left in the bottom of the jar

To the jar, add:

2 tsp. Dijon mustard, or your favourite Smak Dab mustard

2 tbsp. White wine or apple cider vinegar, or juice of 1 lemon

¼ cup extra virgin olive oil

Salt and freshly ground pepper, to taste

Optional add ins:  finely chopped shallot, minced garlic clove, freshly grated ginger (would be exceptional in a citrus jam), a spoonful of chopped fresh herbs