Heat the water for the orzo. Bring a large saucepan full of generously-salted water to a boil.

Brown the mushrooms. Meanwhile, heat 1 tablespoon butter in a large sauté pan over medium-high heat. Add half of the mushrooms and sauté for 5 minutes, stirring and flipping every few minutes, until browned. Transfer the cooked mushrooms to clean plate. Repeat with an additional 1 tablespoon butter and the remaining mushrooms, then transfer the mushrooms to the plate.

Cook the orzo. Add the orzo to the boiling water and cook until 2 minutes shy of al dente.

Sauté the veggies. While the orzo cooks, add the remaining butter to the sauté pan along with the shallot, garlic and crushed red pepper flakes. Sauté for 2 minutes, stirring frequently. Add the cooked mushrooms, heavy cream, a generous pinch of salt and pepper and stir to combine. (If the pasta isn’t quite ready at this point, remove the pan from the heat. Otherwise, continue on.)

Combine. Once the pasta is ready, transfer it to the sauté pan along with 1 cup of the starchy pasta water. Continue cooking, stirring frequently, until the pasta is al dente.

Finish. Remove pan from heat. Add in the Parmesan, spinach, basil, lemon zest and juice (if using), and stir gently until the spinach has wilted. If the pasta seems too dry, add some of the reserved starchy pasta water. Taste and season with salt, pepper and/or extra lemon juice if needed.

Serve. Serve warm, garnished with extra Parmesan, and enjoy!