Preheat oven to 400 degrees. In a bowl, toss fennel and oil together. Season and place on a sheet pan. In a separate bowl, toss asparagus and oil together, season and place on a separate sheet pan. Roast each until browned and tender.
Place the desired amount of arugula on a plate and top with fennel and asparagus. Top with more arugula, if desired.
Garnish with fennel fronds, lemon zest, or parmesan cheese if desired.