Preheat the oven to 400 degrees F (200 degrees C). Lay cod fillets in a baking dish and season lightly with salt and pepper.
Combine water and fish bouillon cube in a bowl. Stir to combine and pour over cod.
Mix bread crumbs, butter, parsley, dill, tarragon, salt, and pepper in a bowl with a fork until crumbly. Sprinkle evenly over cod. Bake in the preheated oven until fish flakes easily with a fork and the crust is golden and crunchy, about 20 minutes.