Cook the pasta: Bring a large pot of salted water to a boil. Cook the pasta until just shy of al dente.
Reserve 1 cup of pasta water, then drain.
12 ounces whole-wheat, chickpea, or regular pasta
Sauté the mushrooms: Heat olive oil in a large skillet over medium-high. Add mushrooms in a single layer and let them brown undisturbed for 3–4 minutes. Stir, add a pinch of salt, and cook until deep golden and tender.
Push to the sides of the pan.
2 tbsp Olive oil, 16 ounces mixed mushrooms , cleaned and sliced
Build flavor: Add butter (if using), onion or shallot, and a pinch of salt. Cook 2–3 minutes until softened. Stir in garlic for 30 seconds until fragrant.
1 small Onion or shallot, finely chopped, 1 tbsp Butter (optional), for extra richness, 3 cloves Garlic, minced
Deglaze: Pour in the broth.
Scrape up any browned bits and simmer for 2–3 minutes to reduce slightly.
1 cup Low-sodium vegetable or chicken broth
Make it creamy: Lower the heat. In a small bowl, whisk Greek yogurt with milk until smooth. Off the heat, stir the yogurt mixture into the skillet.
Return to low heat and warm gently. Do not boil.
¾ cup Plain Greek yogurt (2% or whole), ½ cup Milk (dairy or unsweetened plant milk)
Season: Add lemon zest, a squeeze of lemon juice, black pepper, a pinch of nutmeg, and red pepper flakes if you like heat. Taste and adjust salt.
1 Lemon, zest and juice
Add greens: Stir in spinach until wilted, about 1 minute.
If the sauce seems thick, loosen with a splash of reserved pasta water.
2 cups Fresh spinach (optional)
Toss with pasta: Add the drained pasta to the skillet. Sprinkle in Parmesan and toss over low heat until glossy and well-coated. Add more pasta water a little at a time for a silky finish.
⅓ cup Parmesan cheese, finely grated, plus more for serving
Finish and serve: Top with chopped parsley or thyme, extra Parmesan, and more black pepper.
Serve warm with lemon wedges on the side.
Fresh herbs: Parsley or thyme