Preheat your oven to 400°F (200°C) and line a large rimmed baking sheet with parchment paper.
Trim the woody ends off the asparagus and place them on one side of the baking sheet along with the cherry tomatoes.
Drizzle the vegetables with the olive oil and season with half of the sea salt and black pepper, tossing to coat evenly.
Place the cod fillet on the other side of the baking sheet.
In a small microwave-safe bowl, melt the ghee, then whisk in the lemon juice, lemon zest, minced garlic, chopped parsley, and chopped dill.
Pour the lemon-herb ghee mixture over the cod fillet and season the fish with the remaining sea salt and black pepper.
Bake for 12 to 15 minutes, or until the fish is opaque and flakes easily with a fork and the tomatoes have just begun to burst.
Transfer the fish and roasted vegetables to a plate and drizzle any remaining juices from the pan over the top before serving.