Pierce the sweet potatoes all over with a fork; put them in a microwave-safe dish and microwave until tender, about 20 minutes. Halve the sweet potatoes and scoop the flesh into a bowl. Mash with a fork until fluffy; cover and keep warm.
Meanwhile, pat the turkey dry and sprinkle with 1 tablespoon chile powder and 1 teaspoon salt. Heat the olive oil in a large cast-iron skillet over medium-high heat. Add the turkey and cook until browned, 3 to 4 minutes per side. Transfer to a plate.
Wipe out the skillet and place over high heat. Add the onion and cook, stirring, until dark around the edges, 4 to 6 minutes. Stir in the remaining 1 tablespoon chile powder and the cumin; cook 30 seconds. Add the broth, heavy cream, honey, mustard, and orange zest and juice; simmer until thickened, about 5 minutes. Add the turkey and warm through, 1 minute. Serve with the mashed sweet potatoes.