Preheat your oven to 400 °F and spread your cubed sweet potatoes onto a baking dish sprayed with non-stick cooking spray or lined with aluminum foil. Sprinkle your desired seasonings overtop and roast the potatoes for about 30 minutes, rotating 180 degrees half way through, until fork tender. Set aside.
In a medium sized sauce pan, cook the quinoa in water (or vegetable broth) according to package directions. Fluff and set aside.
While the sweet potatoes and quinoa are cooking, place the de-stemmed kale into a large bowl. Squeeze the lemon juice over the top of the lemon and use your hands to work the acid from the lemon juice into the kale leaves. Be forceful and really "massage" the kale so that the leave break down. You want them to become soft and also decrease drastically in size. Set aside.
Once the sweet potatoes and quinoa are cooked, you can assemble the power bowls. In a bowl place a serving of each of the following: cooked quinoa, roasted sweet potato, massaged kale, black beans, bell pepper and avocado. Top everything with salsa and dig in!