Preheat oven to 425°F. Line a large sheet pan with parchment paper.
Toss halved potatoes with 2 tablespoons olive oil, salt, and pepper. Spread on the sheet pan and bake for 10 minutes.
While potatoes are baking, pat cod fillets dry and season with salt and pepper. In a small bowl, mix remaining olive oil, lemon juice, minced garlic, parsley, and dill.
Remove pan from oven. Add asparagus and cherry tomatoes around the potatoes. Place cod fillets on top of the vegetables.
Drizzle the lemon-herb mixture over the cod and vegetables. Top fish with lemon slices.
Return to oven and bake for 10-12 minutes until cod flakes easily with a fork and vegetables are tender. Serve immediately with extra lemon wedges.