01 -
Preheat the oven to 350°F. Wash and scrub the sweet potatoes under warm running water, pat them dry, and slice each lengthwise in half. Line a large baking sheet with parchment paper. Rub the cut sides of the sweet potatoes with olive oil, season with salt and black pepper, and place them cut sides down on the baking sheet. Bake for about 30 minutes or until soft when poked with a fork. Remove from oven, cool slightly, peel off the skins, and mash the flesh with 2 tablespoons of butter in a large bowl. Set aside.
02 -
In a food processor, combine spinach, garlic, olive oil, balsamic vinegar, cumin, chili powder, and salt. Process for 3-5 minutes until smooth. Transfer the sauce to a medium bowl using a spatula. Set aside.
03 -
Season the flank steak with chili powder, salt, and pepper, and rub in the spices with 1 tablespoon olive oil. Heat a large cast-iron skillet over medium heat for 3 minutes. Add 1 tablespoon olive oil to the skillet. Place the steak in the pan and cook for 5 minutes on one side. Flip, reduce heat to low-medium, and cook for 5 more minutes or until desired doneness (130°F for medium-rare, 145°F for medium). Remove to a plate to rest. Slice the steak against the grain into 1-inch-wide strips.
04 -
In the same skillet, add 1 tablespoon olive oil. Return the sliced steak to the pan, coat with the oil and pan juices, and cook on medium heat for 1-2 minutes. Remove from heat.
05 -
Divide the mashed sweet potatoes and steak among 4 plates. Drizzle the steak with spinach sauce. Add butter and black pepper to the sweet potatoes. Garnish with fresh cilantro or parsley.