Cut the greenery off the fennel bulbs. Then, using a sharp knife, cut the bulbs in half and cut out the triangular-shaped core in each half. Using a knife or a mandolin, thinly slice the fennel.
For the asparagus, take a potato peeler and peel from the bottom of the asparagus stalk upwards to the tip and peel off a few thin ribbons of asparagus. When it gets too thin to peel (after approximately 2 to 4 peels, depending on the thickness of the asparagus), cut the tip off the asparagus and cut the stem into 2-inch pieces, discarding the bottom piece if it’s too woody. Add all the ribbons, tips, and 2-inch pieces to the salad.
In a large bowl or platter, combine the sliced fennel, the prepared asparagus, and the Parmesan cheese.
In a small jar or bowl, whisk together the lemon juice from one fresh lemon – about 1/4 cup, the olive oil, fresh thyme, and salt and pepper. Then drizzle over the fennel, asparagus, and Parmesan. Toss to evenly distribute the dressing.
Slice the remaining lemon into rounds. Garnish with fresh slices of lemon and slivered almonds. Serve immediately.