Warm the butter in a large skillet over medium heat. Add the diced onion and sauté until soft and translucent, about 3 minutes.

Toss in the minced garlic along with the sliced mushrooms, and cook for approximately 7 minutes. Allow the mushrooms to release their moisture and reduce nearly by half, intensifying their earthy flavor.

Sprinkle in the salt, dried thyme, dried parsley, and pepper. Stir in the orzo, and let it toast slightly for about 2 minutes until a pleasant nutty aroma develops.

Pour in the chicken broth and half & half. Reduce the heat to medium-low, cover the skillet, and simmer for 10 minutes – stirring every few minutes to ensure even cooking without over-stirring the pasta.

When the orzo is tender and has absorbed the creamy sauce, fold in the chopped baby spinach and parmesan cheese. Cook until the spinach wilts, then finish with a garnish of fresh parsley before serving.