Combine the orange juice, lime juice, garlic, cumin, 2 tablespoons oil and 1/2 teaspoon salt in a bowl and add the steak, turning to coat; let marinate at room temperature 20 minutes.

Heat the oven to 425°F and line a sheet pan with parchment paper.

Soak the potatoes in cold water 15 minutes, drain, and pat completely dry.

Toss with 2 tablespoons oil, cornstarch and 1 teaspoon salt, spread in a single layer, and bake 35 to 40 minutes, flipping once, until deep golden and crisp.

Sear the marinated steak in a hot skillet over high heat, 3 to 4 minutes per side, until a deep brown crust forms and the center reads warm pink.

Rest the steak on a cutting board 5 minutes, then slice thinly against the grain.

Stir the tomato, onion and cilantro together in a small bowl to make a quick pico de gallo.

Pile the hot fries onto a platter, top with the sliced steak and pico de gallo.

Finish with dollops of mashed avocado, cotija cheese and a drizzle of thinned sour cream.