Grilled Shrimp with Garlic (Gambas al Ajillo)

INGREDIENTS

• 3 tablespoons freshly chopped thyme leaves
• 24 large shrimp, shelled and deveined
• Special equipment: wooden skewers soaked in water
• 3 cloves garlic, thinly sliced
• Salt and freshly ground black pepper
• 1 1/2 tablespoons ancho chili powder
• 3/4 cup olive oil
• 6 cloves garlic, coarsely chopped