Soak cashews for at least 1 hour in water. The longer you soak them the creamier and less chunky the cashew cream will get. So if you have time 8 hours or overnight is best.
Preheat oven to 400ºF or 200ºC.
Wash/scrub the sweet potatoes well. Prick with a fork and place on a baking sheet or in an oven-safe dish. Roast for 45 minutes or until cooked through and fork tender (depends on how big the potato is).
Meanwhile, make the cashew cream. Add all ingredients to a blender/food processor and process until smooth. Add chopped parsley, cilantro or chives if you like. Set aside.
When the sweet potatoes are nearly done, heat cooking oil in a skillet over medium heat. Stir-fry onion for 2-3 minutes. Stir in garlic and cook for 2-3 minutes more or until onions are soft.
Add spices, spinach and lima beans. Stir well and cook until heated through or until the spinach is wilted. Taste and adjust the seasonings if needed.
Once the sweet potatoes are roasted, remove from the oven and let cool slightly. When cool enough to handle, cut, lengthwise, down the center and squeeze open.
Stuff each potato with the spinach-lima bean filling and top with cashew cream. Add fresh chopped parsley, chives or cilantro on top (optional).
Serve immediately.