In the bowl of your slow cooker, layer the thinly sliced onions, 3 tablespoons of salted butter, and then the chicken. Sprinkle the chicken with thyme, sage, chopped garlic, and season generously with salt and pepper. Pour over the wine and broth. Add the sliced mushrooms. Cover and cook on low for 3-4 hours or on high for 1-2 hours.

Preheat the broiler to high. Carefully remove the cooked chicken and most of the caramelized onions from the slow cooker and place them on a baking sheet.

Increase the heat on the slow cooker to high. Stir in the orzo and 1 cup of water. Cover and cook for 20-30 minutes, or until the orzo is al dente. If the orzo needs more liquid, add additional water. Stir in the heavy cream and grated Parmesan cheese.

Arrange the remaining 3 tablespoons of salted butter over the onions on the baking sheet, then top the pan with the shredded Gruyère cheese. Broil for 3-5 minutes, until the cheese is bubbly and golden brown.

Serve the broiled chicken and cheesy onions over the creamy orzo. Enjoy!