Sundried tomatoes either come dried or packed in a jar in oil. If you are using dried sundried tomatoes you will need to rehydrate them. You can do this by soaking them in warm water for 2 hours or placed your sundried tomatoes in a microwave-safe bowl and cover with water. Microwave on high for about 2 minutes. Let cool for a couple minutes. Check they are soft enough that the skins can be easily pierced or cut. Make sure you drain the water off and pat them dry before using them in this recipe. For this spinach sundried tomato chicken recipe I prefer using sundried tomatoes packed in oil.