Prepare the Chicken: Season the chicken on both sides with some of the Italian seasoning, plus the salt and black pepper.

Browning the Chicken: Heat a large nonstick skillet over medium-high heat and brown the chicken for 1 to 2 minutes per side.

Transfer to Slow Cooker: Transfer the chicken to a greased slow cooker.

Add Ingredients: Add the chicken broth, melted butter, mushrooms, chopped onion, minced garlic, and the remaining Italian seasoning.

Cook the Chicken: Cover and cook on high for 1 to 2 hours or on low for 3 to 4 hours.

Add the Orzo: Stir in the orzo, cover again, and cook on high for 30 to 45 minutes, until the orzo is tender.

Combine and Finish: Remove the chicken carefully, stir the orzo mixture, then return the chicken to the slow cooker.

Sprinkle the Parmesan cheese over the chicken.

If using spinach, stir it in during the last 5 minutes of cooking, until wilted.

Cover and cook for 5 to 10 minutes more, until the Parmesan is melted.

Serve: Garnish with fresh thyme or parsley and freshly cracked black pepper, then serve warm.