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.