Sweet Potato Shepherd's Pie With Porcini (Paleo)

Ingredients

• 1 cup dried shiitake mushrooms (and/or porcini)
• 1 medium onion (peeled and diced)
• 1 tablespoon ghee (or coconut oil, butter can also be used)
• 850 g ground beef (about 2 lbs. grass-fed beef mince)
• 2 medium carrots (peeled and finely diced)
• 3 cloves garlic (finely diced)
• 1/2 cup red wine
• 1 1/2 teaspoon sea salt
• 2/3 teaspoon black pepper
• 1 star anise (optional)
• 2 dry bay leaves
• 1 teaspoon mixed dried herbs
• 1 cup chicken stock (water, vegetable or beef stock is also fine)
• 4 tablespoons tomato paste
• 1 tablespoon Tamari (wheat-free soy sauce or coconut aminos, optional)
• 2 teaspoons arrowroot (or tapioca flour for thickening)
• 2 medium sweet potatoes (peeled and cubed)
• 2 tablespoons Parmesan cheese (grated, aged (optional))
• 1 tablespoon butter (or ghee, olive oil)
• 1/2 teaspoon sea salt