In a small bowl, season shrimp with half of salt, half of pepper and red pepper. Set aside.
Heat 1 tablespoon oil in a large heavy bottom skillet over medium-high heat. Add asparagus and cook for about 5 minutes until tender. Remove asparagus from pan and set aside.
Add other tablespoon of oil to pan along with onion and garlic and cook for about 5 minutes or until onion is translucent, stirring frequently.
Add orzo and cook 2 minutes or until lightly toasted, stirring to coat with oil.
Add 2 cups broth and remainder of salt to pan, bring orzo to a boil. Reduce heat and simmer 15 minutes, stirring occasionally.
Stir in remaining 1 ½ cups stock, peas, lemon zest, and shrimp; cook 5 minutes or until shrimp are done. Remove pan from heat. Stir in asparagus, lemon juice, pepper, and Parmesan cheese. Sprinkle with chopped parsley if desired. Serve immediately.