Season steaks on both sides generously with onion powder, salt, and pepper. Add 3 sprigs of fresh thyme on each side of the steaks and place inside vacuum-seal bags and seal.
Place vacuum-sealed bags into a sous vide water bath with the temperature set to 129 degrees F (54 degrees C). Leave in water bath for 1 1/2 hours.
Take steaks out, pat dry with paper towels, and remove, reserving sprigs of thyme.
Heat a cast iron pan over high heat. Drizzle in avocado oil. Sear steaks for about 45 seconds per side. Drop 2 tablespoons butter and garlic into the pan while searing the second side, tilt the pan, and spoon butter on top of steak. Add remaining butter and sear the edges of the steak using tongs, about 45 seconds each.
Remove steaks from the pan and add red wine, Worcestershire sauce, reserved sprigs of thyme, and broth. Let simmer until liquid has reduced by half, 4 to 5 minutes. Strain liquid through a fine-mesh sieve into a bowl. Top steaks with red wine sauce and serve.