1 Tbsp. Lusty Monk Original Sin mustard
1 tsp. crushed red pepper
3 Tbsp. Balsamic vinegar
4 scallions, chopped
1 lb. mixed mushrooms (shiitake, portobello and oyster), sliced 1/2-inch thick
4 cups fresh spinach

Combine first three ingredients in a bowl, toss in mushrooms, mix well, then spoon on top of beds of spinach individually arranged on plates.