Freshly ground pepper SLICE THE TOMATO AND PEELED AVOCADO from stem to tip and fan on plates. Just before serving, heat the olive oil in a medium skillet over medium heat, add the mushrooms and cook, covered, for 5 minutes. Add the garlic, shallots, vinegar and salt. Cook, covered, 1 minute more. Remove the mushrooms and arrange over the avocado and tomato. Give a few turns of the peppermill over each salad as desired. Distribute the dressing equally on the salads.