Remove the beef tenderloin from the fridge and let it come to room temperature prior to cooking, about 1 to 2 hours.

In a small bowl, mix together the softened butter, minced garlic, finely chopped rosemary, and thyme. Set aside.

Preheat your oven to 425°F (220°C). Slice the beef tenderloin in half lengthwise if needed, then trim and tie it with butcher’s twine.

Use paper towels to pat dry any excess moisture from the beef tenderloin, then season both sides with kosher salt and freshly ground black pepper.

Heat avocado oil in a large cast-iron pan over medium-high heat. Once the oil shimmers, add the tenderloin and sear for about 10 minutes total, turning to brown all sides.

Spread the garlic herb butter mixture over the top side of the beef tenderloin. Insert a probe thermometer if available. Transfer the cast-iron pan to the preheated oven and roast for 15 to 20 minutes depending on preferred doneness.

Remove the roast from the oven and transfer it to a cutting board. Let it rest for 10 to 15 minutes.

Remove the twine, slice the roast into 1-inch thick pieces, and serve.