01 -
Fill a large saucepan with water, season generously with salt, and bring to a rolling boil.
02 -
Heat 1 tablespoon of butter in a large sauté pan over medium-high heat. Add half the sliced mushrooms and cook, stirring occasionally, until browned, about 5 minutes. Transfer mushrooms to a clean plate.
03 -
Add another tablespoon of butter to the pan and repeat the browning process with the remaining mushrooms. Transfer to the plate with the first batch.
04 -
Add orzo to the boiling water and cook until about 2 minutes before al dente, then drain, reserving 1 cup of the pasta cooking water.
05 -
In the same sauté pan, melt the remaining tablespoon of butter over medium heat. Add minced shallot, garlic, and crushed red pepper flakes; cook for 2 minutes, stirring frequently. Stir in browned mushrooms, heavy cream, salt, and pepper. Remove from heat if orzo is not ready yet.
06 -
Once orzo is ready, add it to the sauté pan along with 1 cup of reserved pasta water. Cook over medium heat, stirring frequently, until orzo reaches al dente texture.
07 -
Remove pan from heat. Stir in Parmesan, baby spinach, chopped basil, lemon zest, and juice if using. Mix gently until spinach wilts. Adjust consistency with additional pasta water if needed and season with salt, pepper, or extra lemon juice to taste.
08 -
Plate the orzo warm, garnish with extra Parmesan if desired, and serve immediately.