Paleo Turkey Sweet Potato Shepherd's Pie from Thanksgiving Leftovers

Ingredients

• 1 tbsp. olive oil
• 1 large onion (chopped)
• 2 cups celery (chopped)
• 3 cups carrots (chopped)
• 1 tsp. dried ground sage
• 1 tsp. dried thyme
• 1 tsp. dried rosemary
• 1-2 tsp. sea salt
• fresh ground pepper (to taste, omit for AIP)
• 4 cups turkey (chopped)
• ~1 cup gravy
• 1-2 cups turkey broth
• 1 tbsp arrowroot powder
• 1 tbsp. cold water
• 2-3 cups mashed vegetable (I used sweet potato)