Add the potatoes to a large saucepan + add enough water to cover the potatoes. Add 1/2 tsp. of the salt to the pot. With the heat on high, bring the water to a boil. Once it reaches a boil, reduce the heat to medium + simmer for about 15 mins, until the potatoes are tender. Drain the potatoes + then add to a large bowl. Use a potato masher to mash the potatoes. Add the remaining 1/4 tsp. salt, cumin, chili powder + oregano. Mix well until combined.
In a medium skillet, heat the olive oil over medium heat. When hot, add in the kale. Cook for about 2-3 mins., until kale is bright green + tender. Add the mixture to the bowl with the mashed sweet potatoes. Next add in the black beans + mix until well combined.
Place the tortillas on a work surface. Use a spatula to smear about 1/3-1/2 half cup of the filling on of the tortilla. Top with about 1/4 cup of the cheese. Put on skillet to cook.