Preheat oven to 400 degrees F.

Melt ½ cup butter in a saute pan over medium heat and continue to gently simmer until browned, about 4-5 minutes. The butter should smell nutty when ready. Remove from heat and set aside.

Core and cut the pears in half. Slice each half into 6 slices. Gently toss the pears with the sliced red onion, fresh thyme, rosemary, and half of the browned butter. Season with salt and pepper. Transfer the pears to a 9x13 inch baking dish and lay in one even layer. Cover the pan with foil and bake for 30 minutes.

Meanwhile, make the prosciutto gruyere breadcrumbs. Toss together the prosciutto, 1 cup breadcrumbs, ½ cup grated gruyere, ½ teaspoon black pepper, and the remaining browned butter together until well combined.

Remove the pears from the oven and sprinkle the breadcrumbs in an even layer on top. Bake uncovered for 20 minutes or until golden brown. Remove from the oven and let sit for 10 minutes before serving.