In a large non-stick skillet or wok, heat oil over medium high heat. Cook shrimp quickly until pink. Remove to board and chop coarsely. Discard shrimp tails. Add garlic and onion to skillet and cook for 1 minute. Stir in carrots and cook for 2 minutes. Add egg and rice and toss quickly to distribute egg. Stir in soy sauce. Toss in scallions and serve.