Preheat a grill or broiler to high.
In a mortar and pestle, combine the thyme and parsley with the sea salt and pound until well crushed.
Add the lemon juice and drizzle in the olive oil until well combined. Add a pinch of pepper if desired. Set aside at room temperature until you are ready to serve the sardines.
Season the sardines well on both sides with salt and pepper.
Place directly on the grill and cook, turning once, until the skin is crispy and lightly charred, 2 to 3 minutes per side, depending on the size of the fish.
Transfer the fish to a serving platter and drizzle with the herb sauce. Serve immediately, with crusty bread, if desired.
Yield: 4 servings