In a cooking pot, add sweet potatoes, white potatoes, green peas, celery and fennel.
Cover with water, bring to a boil and cook for a few minutes, until the white potatoes become soft enough.
Transfer excess water into a separate bowl and let the cooked ingredients cool down a bit.
Add cooked veggies into the blender. Add butter, together with salt and spices.
Blend until you obtain a creamy consistency. Consider adding a bit of water if your blender has a hard time pureeing the ingredients. A bit more butter could also help with reaching that perfect creamy texture.
Once done, pour into a plate or a bowl, and decorate with a bit of green peas and black pepper. Serve hot or at room temp. Enjoy!