Pre-heat the oven to 425 degrees.
Place the halved butterkin squashes flesh side up in a baking dish, and spread 1 tbsp of butter over the flesh of the squash. Sprinkle with salt and pepper and roast at 425 degrees for 50 minutes. While the squash roasts, you can make the filling.
To make the filling, melt 1 tbsp of butter in a skillet over medium high heat. Add the onion and mushrooms with a pinch of salt and cook over medium high heat for 5 minutes until fragrant and golden.
Add the garlic and the chicken, stir to combine, and cook for 1 minute.
Add the spinach, thyme, and splashes of bone broth and cook until the spinach wilts and the broth cooks off – this takes a few minutes.
When the squashes are done roasting, turn the oven off, and take the baking dish with the squash out. Scoop the chicken/spinach skillet mixture into each half of the butterkin squash, patting the filling down into the middle.
Whisk the GF Panko breadcrumbs and parmesan cheese together in a small bowl and sprinkle over each squash half.
Put the stuffed squashes under the oven broiler on “HI” for 3-5 minutes watching carefully for a beautiful golden color. Every oven broiler can run differently so take a peek after a couple minutes in case yours runs hotter.