Step 1. Ahead of time, pat dry the outside and inside of your turkey with paper towels. Lay the turkey on a sheet pan with a baking rack on top of it and refrigerate uncovered overnight. This is optional but will produce a turkey with crispier skin.
Step 2. Preheat the oven to 350 degrees Fahrenheit. Melt 6 tablespoons of butter and stir in the rosemary, sage, garlic, and a good pinch of salt and pepper.
Step 3. Rub the herb butter mixture all over the outside of the turkey. Cut the remaining butter in half. Carefully lift the breast meat away from the skin on either side of the breast and place a pat of butter between the breast and skin.
Step 4. Place the turkey in a roasting pan or on a sheet pan with a rack to go over it. For easier clean up, you can place aluminum foil, parchment paper or both on the sheet pan under the rack. Set your Thermopro thermometer to the poultry setting (or 165 degrees Fahrenheit) and place one probe in the thickest part of the breast.
Step 5. Place the other probe in the thickest part of the thigh. You can place the thigh probe between the breast and leg or on the side of the thigh, whatever will get you to the thickest part the most easily.
Step 6. Roast the turkey until the desired internal temperature is reached (assume 15-20 minutes per pound). If the breast begins to brown too quickly, you can place a piece of foil on top of the breasts to slow down the browning. You may want to let the internal temperature raise a little higher (170 or so) for the thigh meat.
Step 7. While the turkey is cooking, prepare the sweet potatoes. Pour the sweet potatoes in a large pot and fill with water until the water level is about an inch higher than the sweet potatoes. Heat over medium-high heat until the water begins to boil.
Step 8. Reduce the heat to a simmer and cover the sweet potatoes. Continue boiling until the sweet potatoes are tender. Drain the sweet potatoes, then mash them with the butter, sugar, salt and pepper.
Step 9. Add the milk ¼ cup at a time until the sweet potatoes are well mashed and creamy.
Step 10. When the turkey reaches the desired temperature, allow it to rest for 10-15 minutes. Carefully remove the breast meat and carve in slices across the grain
Step 11. Collect all of the pan juices from under the turkey and strain them into a small bowl. Take a few tablespoons of drippings and whisk in 1 tablespoon of tapioca starch or cornstarch.
Step 12. Pour the slurry back into the rest of the pan juices and stir together until a gravy forms. Pour the gravy over the plated turkey and eat!
ABFD
