Preheat the oven to 400 degrees. Pierce cleaned sweet potatoes with a fork 5-6 times. Wrap in foil and bake in the oven for 30-35 minutes or until medium firmness {you don't want them as soft as you would for mashed sweet potatoes}. Remove from oven and take off foil to let cool.

Slice sweet potatoes lengthwise down the middle. Scoop out the inside of the potato and place in a medium sized bowl. Mash with a fork.

Heat oil over medium heat in a small pan. Add onion and saute for about 5 minutes or until softened. Add garlic and ginger and saute for another 1-2 minutes. Remove from heat and add to the bowl with the potato pulp. Add cilantro, garam marsala and lemon juice. Stir together until well combined.

Spoon mixture back into potato skins and place in the oven for 5-6 minutes or until hot. Top with cashew pieces and serve.