Coat a large nonstick skillet with nonstick spray. Add turkey pieces, season with 1/8 teaspoon salt and cook over medium-high heat for 5 minutes, turning halfway through cooking. Remove to a plate and reserve.Advertisement
Coat skillet with more spray; add onion. Cook on medium-low for 5 minutes, stirring occasionally; add 2 tablespoons of water to prevent sticking if needed. Add mushrooms; cook for 5 more minutes, stirring occasionally. Sprinkle flour over top and stir. Cook for 1 minute.
Stir in half-and-half, nutmeg, hot pepper sauce and remaining 1/4 teaspoon salt. Bring to a boil. Lower heat and simmer 1 minute. Gradually stir in the spinach and cook until wilted. Add turkey and mustard and heat through. Stir in the Swiss cheese until just melted. Serve immediately with cooked noodles.