Preheat oven to 375°.
Cook pasta according to package directions, omitting salt and fat. Drain well.
Combine the flour and salt in a Dutch oven over medium heat. Gradually add milk, stirring constantly with a whisk; bring to a boil. Cook 1 minute or until slightly thick, stirring constantly with a whisk. Remove from heat. Stir in 3/4 cup cheese, stirring until melted.
Heat butter in a large nonstick skillet over medium-high heat. Add shrimp and garlic; sauté 3 minutes. Stir in wine and pepper, and cook 1 minute or until shrimp is done.
Add pasta, shrimp mixture, and peas to cheese mixture, tossing well to combine. Spoon the pasta mixture into a 13 x 9-inch baking dish lightly coated with cooking spray; sprinkle evenly with remaining 1/2 cup cheese. Bake at 375° for 20 minutes or until cheese melts and begins to brown. Garnish with the parsley, if desired. Serve immediately.