In a large skillet, melt butter over medium heat. Add diced shallots and sauté for 3-4 minutes until tender and translucent.

Add sliced mushrooms to the skillet, stirring occasionally for about 10 minutes until browned and tender.

Sprinkle flour over the cooked mushrooms and stir for 1 minute to cook off the raw flour taste.

Gradually pour in chicken broth while whisking continuously. Bring to a simmer and let it cook for 3-5 minutes until thickened.

Slowly whisk in half and half and cook for another 2-3 minutes on low heat until creamy.

Add soy sauce, adjusting seasoning with salt and pepper to taste.

Remove from heat and stir in grated Parmesan cheese and chopped parsley.

Add cooked fettuccine to the skillet and toss gently to coat in the sauce.