Preheat the oven to 425°F.
Prick the sweet potato all over with a fork. Wrap the potato tightly in tin foil and place in the oven. Roast the potato for 1 hour or until tender. Remove the potato from the oven, unwrap it and cut it in half. Set aside to cool completely.
While the potato is roasting, place the lentils, wild rice and water in a medium-sized saucepan over high heat. Bring to a boil and add 1 teaspoon of the salt. Reduce to a simmer and cook, covered, for 40 minutes or until the water is absorbed. Remove the pan from the heat and fluff with a fork. Transfer the rice and lentils to a large bowl and set aside to cool.
Scoop the sweet potato flesh from the skin and add it to the lentil mixture. Add in the cilantro, parsley, garlic, ginger, spices and the remaining salt. Using clean hands, integrate the ingredients into one another until a uniform mixture forms. Form into 8 equal-sized patties and chill for 30 minutes.
When ready to cook, pour an inch of vegetable oil in a large cast iron skillet. Place the skillet over medium heat. Once the oil is shimmering, add the patties to the oil. Fry the patties until crisp on both sides, about 3-4 minutes a side. I did this in stages, working with 3-4 patties at a time.
Transfer the finished burgers to a plate lined with paper towel and place in a 150°F oven to keep warm until ready to serve.