Adjust rack to top position (top and middle positions for 4 servings) and preheat oven to 425 degrees. Wash and dry produce.

Cut potatoes into ½-inch-thick wedges. Toss on one side of a baking sheet with a drizzle of oil, oregano, half the garlic powder (you’ll use the rest later), salt, and pepper (for 4, spread potatoes across entire sheet). Roast on top rack for 10 minutes (you'll add more to the sheet then).

Once potatoes have roasted 10 minutes, remove sheet from oven. Lightly oil opposite side of baking sheet; add empanadas. Bake on top rack, flipping empanadas halfway through, until empanadas are golden brown and potatoes are browned and tender, 15-18 minutes more. (For 4, leave potatoes roasting; place empanadas on a second lightly oiled baking sheet and bake on middle rack.)

Halve, peel, and cut half the onion (whole onion for 4 servings) into ½-inch wedges. Cut tomato into ½-inch wedges. Roughly chop cilantro.

In a small pot, combine rice, ¾ cup water (1½ cups for 4), and a pinch of salt. Bring to a boil, then cover and reduce to a low simmer. Cook until rice is tender, 15-18 minutes.

Keep covered off heat until ready to serve.

Pat steak* dry with paper towels; slice into 1-by-3-inch strips (the strips don’t need to be perfect—a rough 1 by 3 inches is fine!).

In a medium bowl, combine cornstarch, half the cumin (all for 4 servings), remaining garlic powder, salt, and pepper.

Add steak; toss until thoroughly coated.

Heat a drizzle of oil in a large pan over medium-high heat. Add steak and cook, tossing occasionally, until a crust forms, 4-6 minutes (the steak will finish cooking in the next step). Turn off heat; transfer to a plate. Wipe out pan.

Heat another drizzle of oil in pan used for steak over medium heat. Add onion wedges and tomato; cook, stirring occasionally, until slightly tender, 4-6 minutes.

Add steak, soy sauce, Sriracha, ⅓ cup water, 2 tsp vinegar, and ¼ tsp sugar (⅔ cup water, 4 tsp vinegar, and ½ tsp sugar for 4 servings). (Reserve remaining vinegar for another use.) Cook, stirring, until sauce has thickened and steak is cooked through, 1-3 minutes. Taste and season with salt and pepper if desired.

In a small bowl, whisk together mayonnaise and chimichurri. Season with salt and pepper if desired.

Fluff rice with a fork; stir in 1 TBSP butter (2 TBSP for 4 servings). Garnish with half the cilantro.

Place potatoes on a serving dish; top with lomo saltado. Garnish with remaining cilantro. 

Serve rice, potatoes and lomo saltado, and empanadas family style. Serve with creamy chimichurri sauce on the side.