Preheat the grill to medium high or heat a grill pan over medium heat.
2. Brush the lettuce, radicchio and lemon halves with olive oil and season with salt and pepper.
3. Place the lettuce, radicchio and lemons cut side down in the pre-heated surface and grill for 5-7 minutes until the lettuces and radicchio are a bit charred and slightly limp. Grill the other side for another 2 minutes
4. Remove the lemons when they are very dark brown (about 10-15 minutes.
5. Transfer to a platter and drizzle with extra virgin olive oil and sprinkle with sea salt.