Start by drying the steak thoroughly with paper towels; season both sides with salt, pepper, garlic powder, and onion powder. Let it rest at room temperature for 15-20 minutes.

In a mixing bowl, whisk together sour cream or Greek yogurt, Dijon mustard, fresh herbs, garlic powder, salt, and pepper until smooth. Cover and refrigerate for at least 10 minutes.

Slice the zucchini into thick rounds and toss in olive oil, salt, and pepper. Preheat your grill pan over medium-high heat. Grill zucchini for 2-3 minutes on each side.

Heat a grill pan with olive oil over medium-high heat. Cook the seasoned steak for 3-4 minutes on each side for medium-rare. Let it rest for 5-10 minutes.

Prepare the bowl base with cooked rice or mashed potatoes, then slice the rested steak against the grain and arrange it on top, followed by the grilled zucchini. Drizzle with the creamy herb sauce.