Preheat oven to 400 degrees F. Toss mushrooms in 1 Tb. olive oil and 1 tsp. lemon juice. Spread on large baking sheet and bake 15 minutes. Drain off liquid. Cool slightly. In a bowl, combine mushrooms, red pepper, basil or mint, and pine nuts.
Whisk together dressing ingredients; toss into mushroom mixture.
Place lettuce on 4 salad plates and spoon mushroom mixture on top.