1. Get ready. Preheat your oven to 400°F.
2. Roast the garlic. Use a serrated knife to trim the top off the whole head of garlic, exposing the cloves but keeping the bunch intact. Set on a large sheet of foil, drizzle generously with olive oil, and close the foil to wrap. Roast in the heated oven for about 10 minutes or until slightly tender and fragrant, then remove from the oven and let cool briefly.
3. Process the garlic. Once cool enough to handle, peel and crush or chop the roasted garlic as finely as possible.
4. Make the sauce: In a small bowl, combine the roasted garlic, cilantro, lime juice, white wine, extra virgin olive oil and harissa. Whisk together and set aside.
5. Cook the shrimp: Heat a cast iron skillet, grill, or indoor griddle over high heat. Pat shrimp dry and season with salt and pepper, drizzle a little extra virgin olive oil and toss. Arrange on the preheated surface and cook for about 2 minutes per side, or until the shrimp turns just pink. Even the largest shrimp will be ready within about 5 minutes, so be careful not to overcook it.
6. Finish and serve. Immediately toss the grilled shrimp in the delicious roasted garlic sauce and serve immediately.