Preheat oven to 350 degrees Fahrenheit.

Place onion slices and garlic in a roasting pan. Place oyster steaks on top. Season well with kosher salt and pepper. Drizzle with one-fourth of the maple syrup.

Place remaining maple syrup, bourbon, half a teaspoon kosher salt and half a teaspoon ground pepper in a heavy saucepan. Bring to a boil and continue to cook until it is reduced to a sticky glaze. Stir occasionally so it does not burn.

Roast steaks, covered, for one hour. Carefully remove from oven. Pour off most of the liquid accumulated in the pan.

Pour half the glaze over the steaks and return to the oven. Continue roasting, uncovered, for 20 minutes or until a nice crust has formed.

Remove from oven and let the steaks rest for five minutes.

Slice across the grain and drizzle remaining glaze on the meat.