Shiitakes, which are sold in my supermarket along with cremini and button mushrooms, are powerhouse mushrooms. Along with the B-vitamins and minerals that all mushrooms contain, the shiitake contains all 8 amino acids, unusual for a plant, and the essential fatty acid linoleic acid, as well as an immune-boosting chemical component called lentinan. When you pan-cook them over high heat, as you do here, the flavor is very intense, because of the natural msg that all mushrooms contain.
Mix together the vinegar and lemon juice with the garlic, salt, pepper, and Dijon mustard using a fork or a small whisk. Whisk in the olive oil and the yogurt or buttermilk if using. Set aside.
02Combine the spinach, nuts, celery, and goat cheese in a salad bowl.
03Heat a pan over medium high heat. Add 1 teaspoon oil and when very hot, add the mushrooms. Shake the pan once, then let the mushrooms cook without moving them around until they begin to sweat and soften (watch closely). After about a minute or two, when they have begun to sear and release moisture, you can move them around in the pan. Cook for about 5 minutes, season to taste with salt and pepper and remove from the heat. Add to the spinach mixture and toss with the dressing. Serve at once.