Remove the steak from the refrigerator and allow it to sit at room temperature briefly. Rub both sides with olive oil and season with salt, black pepper, most of the garlic powder, and most of the smoked paprika.

Slice the zucchini into thick rounds or lengthwise strips. Toss lightly with olive oil, salt, and black pepper.

Preheat an outdoor grill or grill pan over high heat. Grill the zucchini for 2–3 minutes per side, or until tender with visible grill marks. Transfer to a plate.

Place the steak on the hot grill and cook for approximately 4–5 minutes per side for medium-rare, depending on the steak's thickness and your preferred doneness. For food safety, use an instant-read thermometer to check the center rather than relying only on cooking time.

Transfer the steak to a cutting board and let it rest for 5–10 minutes before slicing thinly against the grain.

Meanwhile, cook the quinoa according to the package directions. Once tender, fluff it with a fork and season with a small pinch of salt and a drizzle of olive oil if desired.

Make the creamy sauce by combining the sour cream or Greek yogurt, Dijon mustard, remaining garlic powder, remaining smoked paprika, a pinch of salt, and an optional splash of lemon juice. Stir until smooth and creamy.

Divide the quinoa between serving bowls. Add grilled zucchini and sliced steak, then finish your Grilled Steak Bowl with a generous drizzle of creamy sauce.