To make the butter: In a small bowl, add the butter, chives, thyme, and garlic. Stir to combine completely. Set aside.
Allow steaks to come to room temperature and pat dry with a paper towel. Preheat the oven to 400°F.
In a large cast iron skillet, add the olive oil to coat the pan. Put over high heat.
Generously salt and pepper both sides of the steaks. Add the steaks to the cast iron and sear each side for 2 minutes.
Transfer to the oven for 6 to 8 minutes, cook until desired doneness and depending on the thickness of the tenderloins. Internal temperature should be about 130°F to 140°F for medium rare, which is how I cooked these.
While the steaks are in the oven, add 1 tablespoon of the herb butter into a large skillet. Add the asparagus and cook over medium/high heat, until asparagus is al dente. Remove from heat.
When the steaks are done cooking, remove from the oven. Add a pad of the herb butter on top of each one and let rest for 5 minutes before serving.
Serve with asparagus and bread, use the extra herb butter for bread!