Bring the steak to room temperature, pat dry, and rub with olive oil, salt, pepper, garlic powder, and smoked paprika.
Preheat your grill or grill pan over high heat.
Toss zucchini slices with remaining olive oil and a pinch of salt.
Grill zucchini for about 2–3 minutes per side until tender and charred.
Grill the steak for about 4–5 minutes on each side for medium-rare doneness, then let it rest.
Cook quinoa according to package instructions.
Combine sour cream, Dijon mustard, garlic powder, smoked paprika, salt, and herbs in a bowl. Add lemon juice if desired.
Slice the rested steak against the grain into thin strips.
Assemble the bowl by layering grains, grilled zucchini, and sliced steak, then drizzle with creamy sauce.
