Preheat your oven to 400°F (200°C).

In a dry skillet over medium heat, toast the fennel seeds until fragrant, about 2-3 minutes. Remove from heat and let cool slightly.

Once cooled, crush the fennel seeds using a mortar and pestle or a rolling pin. Combine the crushed fennel with the orange zest and set aside.

Pat the ribeye steaks dry with paper towels. Rub both sides with olive oil and season generously with salt and pepper.

Press the fennel-orange mixture onto both sides of the steaks, ensuring an even coating.

In a large oven-safe skillet over high heat, sear the ribeye steaks for about 3-4 minutes on each side, until a nice crust forms.

Transfer the skillet to the preheated oven and cook for an additional 5-7 minutes for medium-rare, or until desired doneness is reached.

In a mixing bowl, combine the softened butter, chopped tarragon, minced shallot, Dijon mustard, salt, and pepper. Mix until well combined. Set aside.

Once the steaks are done, remove them from the oven and let them rest for 5 minutes. This allows the juices to redistribute.

Serve the ribeye steaks topped with a generous dollop of tarragon-shallot butter.