Fill your sous vide container with water and set the sous vide circulator to 130°F for medium-rare (adjust to 140°F for medium or 125°F for rare).

Pat the steaks dry with paper towels. Season generously with salt, pepper, and garlic powder.

Place the steak in a vacuum-seal bag or resealable freezer bag. Add rosemary and/or thyme if using. Seal the bag using a vacuum sealer or the water displacement method.

Submerge the sealed steaks in the preheated water bath. Cook for 1.5 – 2 hours, depending on the steak thickness.

Make the garlic butter sauce. About 10 minutes before the steaks finish cooking in the water bath, melt the butter in a small skillet over medium heat. Add the minced garlic and sauté until it begins to turn golden brown. Remove from heat and season with salt and pepper to taste.

Remove the steaks from the bags and pat them dry with paper towels.

Sear the steaks. Heat a skillet or cast-iron pan over high heat and add a tablespoon of butter. Sear each steak for 1 minute per side until a golden-brown crust forms.

Transfer the steaks to a cutting board and let them rest for 5-7 minutes. Slice the steaks and drizzle with the garlic butter sauce. Garnish with chopped parsley.