Slice steak tips into roughly 3/4" size pieces.

Place the steak bites into a mixing bowl and toss with one tablespoon of oil until evenly coated. Add 2 tablespoons of Cajun seasoning and mix until the steak is evenly seasoned. Set aside.

Heat 2 tablespoons of oil in a large heavy-bottom skillet over high heat until the oil is shimmering and just starting to smoke. Add steak bites in batches and allow them to sear. When the steak is all seared, remove from pan, and reduce heat to medium.

Deglaze the pan with white wine, being sure to scrape up all the brown bits on the bottom of the pan. Add the butter to the pan and allow it to melt. Add the mushrooms and move them around until they are coated in the fond. Then, add the jalapeños and cook for 2 minutes.

Add the steak bites back into the mushroom and butter mix and fold in to coat all the steak.

Spoon the steak over top of garlic mashed potatoes and pour the remaining butter sauce over the top.