In a large bowl, combine Cajun seasoning. Add the cubes of steak and toss to coat. In a separate bowl, combine butter and garlic and set aside.
Heat 2 tsp. of oil in a skillet over medium to high heat. Sear the steak (if necessary, in batches) for 2-3 minutes on each side until brown. Add extra oil as needed. Remove from heat and add garlic butter to the steak and toss to coat.
Serve warm.