Slice steak into thin strips and toss with chili powder, cumin, garlic powder, onion powder, salt, and pepper.

Heat olive oil in a large skillet over medium-high heat and cook steak until browned and cooked to desired doneness, about 3-5 minutes.

Combine rice, water, and salt in a saucepan, bring to a boil, then reduce heat, cover, and simmer for 15-20 minutes until water is absorbed.

Fluff the cooked rice with a fork and, if desired, stir in fresh cilantro and a squeeze of lime juice for cilantro-lime rice.

Roast tomatillos, jalapeño, onion, and garlic on a baking sheet at 400°F (200°C) for 15-20 minutes until softened and slightly charred.

Transfer roasted vegetables to a blender, add cilantro, lime juice, and salt, then blend until smooth.

Adjust seasoning as needed and set aside.

Combine white vinegar, water, sugar, and salt in a small saucepan and bring to a simmer, stirring until sugar and salt dissolve.

Place sliced red onions in a heatproof jar and pour the hot vinegar mixture over them, ensuring they are fully submerged.

Let cool to room temperature, then cover and refrigerate for at least 30 minutes before serving.

Divide cooked rice among serving bowls.

Top with steak, black beans, corn, salsa, shredded lettuce, sour cream (or Greek yogurt), cheese, diced avocado, and lime wedges.

Add optional toppings like queso, guacamole, jalapeños, salsa verde, or pickled red onions as desired and serve immediately.