Ancho Chile Flank Steak and Sweet Potato Tacos

INGREDIENTS

flank steak

1/4 cup

fresh lime juice

1/4 cup

chopped fresh cilantro

1/2 tsp

garlic powder

1 tbsp

plus 1 tsp. ground cumin, divided

1 tbsp

plus 1 tsp. ancho chile powder, divided

4 tsp

kosher salt, divided

1/4 cup

plus 2 Tbsp. olive oil

1/2 lb

fresh tomatillos, husks removed

1 1/2 lb

sweet potatoes, peeled and cut into 3/4-inch pieces

large red onion, cut into 1/2-inch pieces

Flour tortillas, sour cream, fresh cilantro