In a medium bowl, whisk together all marinade ingredients: lime juice, olive oil, chili powder, cumin, smoked paprika, oregano, and salt. Add the sliced skirt steak or flank steak and toss to coat thoroughly. Let it rest on the counter for 15-30 minutes (or 10 minutes if rushed).

While the steak marinades, heat a large skillet over medium-high heat with a teaspoon of oil. Add the riced cauliflower and a pinch of salt. Sauté quickly for 3-5 minutes until tender-crisp and lightly warmed. Remove and set aside in serving bowls.

Wipe out the skillet and return to high heat. Add a tablespoon of oil and toss in the sliced bell peppers and onions. Cook hot and fast, tossing occasionally, until brightly colored, softened, and starting to blacken at edges, about 5-7 minutes. Move to a clean plate.

Wipe the skillet again. Return to high heat. Remove marinated steak from liquid (discard marinade). Lay steak strips in a single layer in the hot skillet. Cook for 1-2 minutes per side for medium-rare, or longer for desired doneness (about 3-5 minutes total). Remove immediately, tent with foil, and rest for 5 minutes.

Add the sautéed peppers and onions back into the skillet with the rested steak strips. Toss gently to combine and warm through.

Divide the steak and veggie mixture over the prepared cauliflower rice. Top generously with diced avocado, chopped cilantro, salsa, Greek yogurt (if using), and a squeeze of fresh lime. Serve immediately.