Heat your sous vide to 125ºF.

Combine the ground bison and onion soup mix.

Divide the ground bison into equal portions and shape them into three 8-ounce patties. Season with garlic powder, kosher salt, and pepper.

Place each burger in its own zipper-lock or vacuum food-saver bag. Place in the water bath, and allow to cook for 1 hour.

Remove the bags from the water bath. Gently remove the burgers from the bag and pat them very dry. Season with additional garlic powder, salt, and pepper.

Heat your grill to very hot. Add the burgers and sear on the first side until well-browned, 45 seconds to 1 minute. Flip burgers and top with cheese. Continue to sear until the second side is well-browned and the cheese is melted, 45 seconds to 1 minute.

Transfer burgers to a plate and let rest for 5 minutes.

Serve on buns with tomatoes and your favorite toppings.