Melt 1 tablespoons butter with 1 tablespoon oil in a large skillet over medium-high heat. Add onion, season with salt and pepper, and cook, stirring occasionally, until softened and lightly golden, 4-5 minutes. Add garlic and cook for 1 minute. Stir in wine and cook until liquid is reduced by half, about 2 minutes.

Add remaining 1 tablespoon butter, and mushrooms. Cook, stirring occasionally, until mushrooms are lightly golden, about 5 minutes. Add cream and nutmeg and cook until slightly thickened, about 2 minutes. Season to taste with salt and pepper.

Add in baby spinach and pasta. Toss well and divide among two plates.

Top with more freshly grated pepper and parmesan cheese if desired.