Adjust rack to middle position and preheat oven to 425 degrees. Wash and dry produce.

Peel and dice sweet potato into ¼-inch pieces. Halve, peel, and cut onion into ½-inch-thick wedges. Cut cauliflower into bite-size pieces if necessary. Roughly chop walnuts. Roughly chop cilantro. Quarter lemon.

Toss sweet potato, onion, and cauliflower on a baking sheet with a large drizzle of oil, half the Mexican Spice Blend (you’ll use the rest in the next step), salt, and pepper.

Roast on middle rack until veggies are browned and tender, 15-20 minutes.

Meanwhile, pat steak* dry with paper towels; season all over with remaining Mexican Spice Blend, salt, and pepper.

Heat a drizzle of oil in a large pan over medium-high heat. Add steak and cook to desired doneness, 3-5 minutes per side.

Turn off heat; transfer to a cutting board to rest.

In a small bowl, combine sour cream with half the chimichurri (you’ll use the rest in the next step).

Once veggies are done, transfer to a medium bowl; stir in walnuts, half the cilantro, half the feta (all for 4 servings), and remaining chimichurri. Toss until evenly coated.

Thinly slice steak against the grain.

Divide steak and sweet potato jumble between plates. Top jumble with remaining cilantro and a squeeze of lemon juice. Drizzle with creamy chimichurri and serve.