1. Clean the casserole and set aside.
2. Wash the sweet potatoes and set aside.
3. Knead the tin foil into a number of tin foil balls.
4. Spread the tin foil balls evenly on the bottom of the casserole (you can also use a grill or small stones instead)
5. Lay the other two large tin foils across the tin foil balls.
6. Place the sweet potatoes evenly on the tin foil.
7. Put the lid on and roast on high heat, turning over every 10 minutes.
8. Try it with chopsticks, it can be easily penetrated and cooked. Put the lid on and use the remaining temperature of the casserole to simmer for a few minutes, then you can start eating.
9. It's soft and sweet, and it's oily.
1. Don't use ordinary casserole for roasting. I use the black casserole which is dry-boiled and fast-cooled, so it’s no problem.
2. When turning over, you can wipe off the moisture around the sweet potatoes so that the roasted sweet potatoes will be drier and not wet.