Peel, define and butterfly shrimp. In a bowl, mix shrimp with garlic, 1 tablespoon of the oil and salt. Marinate, refrigerated, 1 hour.
Heat 2 tablespoons of the oil in a large saute pan over high heat. Add shrimp, spreading them so cut surface lies flat. Weight shrimp with a slightly smaller saute pan or other weight, press and sear 30 seconds, and remove to a plate. Add mariner and chicken stock to pan. Reduce rapidly over high heat 5 minutes, or until liquid has evaporated. Return shrimp to pan, toss well and cook until shrimp are warmed through. Season to taste with crushed red pepper, salt and pepper. Serve immediately, sprinkled with chopped parsley.