Heat a nonstick skillet over medium high heat. Add shredded Swiss in small, 2-inch piles to the hot skillet. When the cheese fries to a light golden color at the edges, about 1 minute, and can be moved with a thin spatula, turn the cheese rounds, cook another 15 seconds, then remove rounds from the skillet and transfer rounds to a work surface to cool. The cheese crisps will cool within a minute or so. Repeat to form 12 to 16 crisps, 3 or 4 per salad. Crisps may also be flavored with cracked black pepper and chopped thyme or other herbs.
Place spinach in a bowl. After slicing your apple, squeeze a wedge of lemon over the slices to keep them from browning. Toss apples with spinach. For dressing, combine thyme, Dijon mustard and vinegar with a whisk. Stream in olive oil while continuing to whisk dressing. Pour dressing over the salad and toss to coat greens and apple evenly. Pile salad onto cheese roundss and serve.