Heat oven to 200°c (400°f). Coat a large casserole dish with cooking spray.

Bring a large saucepan of salted water to a boil and cook spaghetti according to package directions. Drain and set aside.

In a large skillet over medium-high, heat oil. Add mushrooms and garlic, then season with salt and pepper. Saute until well browned and mushrooms release all their liquid, about 10 minutes. Add asparagus and red pepper and cook for another 4 minutes.

Stir in 1 teaspoon of the onion powder and one teaspoon of the paprika and sherry. Cook for one minute, then remove from heat. Add turkey and set aside.

In a small saucepan over low heat, bring half-and-half to a simmer. Whisk in instant-blend flour, then bring to a boil. Cook until thickened about one minute. Remove pan from heat and stir in Parmesan. Season with salt and pepper.

In a small bowl, stir together panko, garlic powder, parsley, remaining onion powder, remaining paprika.

To assemble, stir cooked spaghetti and cream sauce into skillet with turkey and vegetables. Spoon mixture into prepared casserole dish, then sprinkle seasoned panko over it. Spritz top of panko crumbs with cooking spray then cook for 10 - 15 minutes or until golden.