Cook the pasta according to the directions on its package. When the pasta is done, scoop out 1 cup of the pasta water. Set it aside. Drain and rinse the pasta.
In a large skillet, heat the oil over medium-high heat. Add garlic and shrimp. Cook for 1 to 2 minutes, until the shrimp turns pink.
Add peas, artichoke hearts and 1/3 cup of the pasta water. Lower the heat to medium. Cover and cook for 1 more minute.
Add the cooked pasta, green onions, lemon juice and pepper. Toss to coat evenly.
Add more cooking water if the pasta is too dry. Serve.