Preheat your oven to 350 degrees. Lightly grease a large baking sheet, set aside.
Heat up a large skillet to medium high heat. Coat with 2 tbsp oil, add sausage and begin to cook. Cook for about 5-7 minutes until cooked through, continuing to break up the sausage with a wooden spoon. Once cooked, set aside. Keep the pan hot.
Add in leeks, apples, and pecans to the pan. Saute for another 4-5 minutes, or until mixture is fragrant and browned.
Pour mixture into a medium sized bowl. Add in cranberries, fresh sage, and whisked eggs. Stir around so all ingredients are well mixed.
Mix the remaining oil with crushed garlic. Place the mushrooms inside the baking sheet, and brush the caps of each mushroom with oil/garlic mixture.
Spoon the mixture in each mushroom cap.
Place inside the oven and bake for 25 minutes, or until mushrooms are browned. Serve hot!