In a large bowl add the jam & vinaigrette & whisk well.
Stir in the mustard, salt & pepper to combine thoroughly.
Slowly add the olive oil & continue to whisk briskly to emulsify.
*That's it! Though my recipe calls for marmalade, I've made this with all types of jam; marmalade, mandarin, plum, blackberry, even strawberry, it's very versatile. Saves a ton of money compared to store bought salad dressing, saves a ton of calories too and it just tastes better!