Preheat oven to 450 degrees.

In a large skillet on the stove, melt butter and stir in olive oil. Toss in chopped onions, cover and cook over medium heat for about 45 minutes or until caramelized onions are desired color. Remove onions and set aside.

In same skillet, melt second tablespoon of butter, stir in garlic and then mushrooms and cook about 8-10 minutes over medium.

When ready for steaks, place your cast iron skillet in the oven for 10 minutes. While pan is heating, brush a bit of olive oil on each steak and sprinkle salt and pepper liberally over both sides of steaks. When cast iron is heated, carefully remove from the oven place on your stovetop over medium heat.

Place your steaks in your cast iron skillet and sear for 2 minutes. Flip your steaks over and put back in the oven for 6 minutes.

Remove and put your cast iron skillet back on stove over low heat.

Put skillet back on stovetop over low heat. Flip your steaks again and top with butter. Brush the butter over the tops of the steaks continually coating the steak for about 1-3 minutes.

Use a meat thermometer to check for doneness. Once your steaks are done, remove from pan and let rest five minutes before slicing.

Grill some garlic bread. Top with bacon, sliced steak and caramelized onions and mushrooms.

If desired, top with chopped cheese and basil. Serve.