Preheat oven to 350 degrees F.
Remove the stems from the mushrooms and chop; reserve the caps. Heat 2 tablespoons of the oil in a large sauté pan. Add onion and cook until softened; about 5 minutes. Add chopped stems and cook over high heat until they begin to dry; about 5 minutes. Stir in garlic and cook until fragrant; about 30 seconds. Transfer mixture to a bowl and set aside.
24 large fresh mushrooms, button or cremini mushrooms work great, 4 tbsps olive oil, divided, 1/2 cup chopped yellow onioin, 1 tbsp minced garlic
Heat remaining 2 tablespoons of oil in the same pan. Cook pork, breaking it up with a spoon, until cooked through. Stir in cinnamon, nutmeg, fennel seed and orange zest. Add cooked mushroom-onion mixture and bread crumbs; mix well. Season to your own taste with salt and pepper.
1/2 lb ground pork, 1/2 tsp ground cinnamon, 1/4 tsp ground nutmeg, 1 tsp fennel seed, 1 tbsp grated orange zest, 1/4 cup dried bread crumbs, salt and pepper to taste
Stuff pork mixture into mushroom caps. Place mushrooms in a baking pan and drizzle chicken broth around them. Bake until cooked through; about 20 minutes.
1 cup low sodium chicken broth
Place mushrooms on a platter and drizzle with broth from the pan, serve warm.