Cook spaghetti according to package directions. Drain, reserving 1/2 cup pasta water., Meanwhile, in a large skillet, heat oil over medium heat. Add shrimp, garlic and rosemary; cook and stir 3-4 minutes or just until shrimp turn pink. Stir in spinach; cook, covered, until slightly wilted., Add spaghetti, lemon juice, salt and pepper; toss to combine, adding reserved pasta water as desired. Sprinkle with cheese. Remove from heat; let stand, covered, until cheese is softened.