In a deep skillet, add 1/2 inch Oil, heat until hot, add Potatoes & cook to golden brown (7-10 Min), Drain well.
Pour off remaining oil add the Butter ,sauté the Onions, then add Garlic, Mushrooms & Sausage & sauté until done (about 5 Minutes).
Add back the potatoes, the Green onions. Season to taste with steak sauce & Cajun seasoning. Serve Warm.