Pat the steak completely dry with paper towels. Season both sides generously with garlic powder, onion powder, salt, and black pepper. Let rest at room temperature for 15-20 minutes.

In a small bowl, whisk together sour cream or Greek yogurt, Dijon mustard, chopped fresh herbs, garlic powder, salt, and pepper until smooth. Refrigerate the sauce while you prepare the other components.

Toss zucchini slices with olive oil, salt, and pepper in a bowl, ensuring they're well coated.

Heat your grill pan or cast iron skillet over high heat with a small amount of oil. Once very hot, add the seasoned steak.

Cook steak for 3-4 minutes per side for medium-rare (130°F internal temperature), or adjust time based on your preferred doneness. Use a meat thermometer to check.

Remove steak from heat and let rest for 5-10 minutes to allow juices to redistribute.

While steak rests, grill zucchini slices in the same pan for 2-3 minutes per side until tender with light char marks. Set aside.

Slice the rested steak against the grain into thin strips.

Build your bowls: Start with cooked rice or mashed potatoes as the base. Layer grilled zucchini on top, add sliced steak, and drizzle generously with creamy herb sauce.

Garnish with extra fresh herbs and serve immediately while warm.