A.1. Sour Cream: Mix ingredients. Refrigerate until ready to use.
CARAMELIZED Onions & Mushrooms: Heat oil in skillet on medium-low heat; add onions and mushrooms. Cook until onions are caramelized, stirring occasionally. Deglaze pan with vinegar and jelly; set aside.
FOR each serving: Brush each tomato slice with 1/8 tsp. oil. Broil until lightly charred, then finely chop.
GRILL 1 burger patty to desired doneness.
FILL 1 roll with 1 cooked burger, 1 cheese slice, 1 Tbsp. A.1. Sour Cream, 1 Tbsp. charred tomatoes and 1 Tbsp. Caramelized Onions & Mushrooms.