Instructions:

1. Pat beef tenderloin steaks dry with paper towels. Season generously on all sides with salt and freshly ground black pepper. Let sit at room temperature for 15-20 minutes.
2. Wash zucchini and trim the ends. Cut each zucchini in half lengthwise, then slice into 1/2-inch thick crescent-shaped pieces. Mince garlic and chop fresh thyme and rosemary.
3. Heat 2 tablespoons of olive oil in a large cast-iron skillet or heavy-bottomed pan over medium-high heat until shimmering and almost smoking. Carefully place steaks in the hot pan, ensuring not to overcrowd (cook in batches if necessary). Sear for 2-3 minutes per side for medium-rare, or longer for desired doneness.
4. During the last minute of cooking, add 2 tablespoons of butter, half of the fresh thyme, and half of the rosemary to the pan. Tilt the pan and spoon the melted butter and herbs over the steaks repeatedly for about 30 seconds.
5. Remove steaks from the pan and place them on a cutting board or plate. Tent loosely with foil and let rest for at least 5-10 minutes. This is crucial for juicy steaks.
6. In the same pan (or a separate pan if preferred, after wiping out excess beef fat), add the remaining 1 tablespoon of olive oil over medium heat. Add minced garlic and cook for 30 seconds until fragrant.
7. Add the sliced zucchini to the pan along with the remaining fresh thyme and rosemary. Sauté for 5-7 minutes, stirring occasionally, until the zucchini is tender-crisp. Season with salt and pepper to taste.
8. Slice the rested beef tenderloin against the grain (if desired, or serve whole). Divide the beef and garlic herb zucchini among four plates. Garnish with fresh parsley if using and serve immediately.