Why would a sweet potato still be somewhat hard after being cooked for one hour at 400 degress?

- One hour may not be enough time to fully cook a sweet potato, especially if it was a particularly large or dense one.

2. Size and shape:

- The shape and size of the sweet potato can also affect cooking time. Longer, thinner sweet potatoes will cook more quickly than shorter, thicker ones, as heat will take more time to reach the center of a thicker vegetable.

3. Oven temperature:

- Some ovens may not be as accurate as you think, and could be running at a lower temperature than indicated.

- Ensure your oven is preheated to the correct temperature before roasting the sweet potato.

4. Microwave pre-cooking:

- Microwaving the sweet potato for a few minutes before roasting it can help speed up the cooking process and ensure it is evenly cooked throughout.

5. Quality of sweet potato:

- The quality of the sweet potato itself may also be a factor. A sweet potato that is not fresh or has been improperly stored may take longer to cook or may never soften properly.