Cook pasta according to package directions, omitting salt and fat. Add asparagus during last minute of cooking time. Place peas in a colander. Drain pasta mixture over peas; set aside.
Melt butter in a skillet over medium-high heat. Add garlic to pan; sauté 1 minute. Combine broth and cornstarch in a small bowl; stir until well blended. Add broth mixture to pan; bring to a boil. Cook 1 minute or until thick, stirring constantly. Remove from heat. Stir in cream, juice, salt, 1/4 teaspoon black pepper, and red pepper. Add pasta mixture to broth mixture; toss gently to coat. Garnish with coarsely ground black pepper and lemon slices, if desired. Serve immediately.