Preheat oven 400° F. Bake pastry shells according to package directions; set aside.
Toss asparagus and red pepper with olive oil in medium bowl. Place on baking sheet with sides.
Bake for 15 minutes. Let cool. Combine evaporated milk, flour, tarragon, mustard, salt, and white pepper in medium saucepan over medium-high heat. Cook, stirring constantly, until sauce begins to thicken. Add Brie and continue to stir until melted. Add lemon juice and roasted vegetables; cook for one more minute, stirring occasionally.
Spoon 1/3 cup mixture into individual shells. Top with pastry rounds. Serve immediately.Servings: 6