"Mahi-Mahi was made for summer...."
butter, divided
extra-virgin olive oil, divided
(4-oz.) mahi-mahi fillets
Kosher salt
Freshly ground black pepper
asparagus
cloves garlic, minced
crushed red pepper flakes
lemon, sliced
Zest and juice of 1 lemon
freshly chopped parsley, plus more for garnish