1.Heat The Olive Oil In A Large Skillet Over Medium Heat. Season Pork Tenderloins With Salt, Pepper, And Garlic Powder. Cook Pork In The Oil, Turning Until Browned On All Sides, 5 To 6 Minutes. Remove From Pan, And Set Aside. In The Same Skillet, Cook Onion And Mushrooms Until They Brown Lightly And Begin To Soften; 3-5 Minutes. 2.Pour Wine Into Slow Cooker; Stir In The Onion And Mushrooms. Place Browned Pork On Top Of The Vegetables. 3.Combine Mushroom Soup, Dijon Mustard, And Sour Cream In A Bowl. Spread Mixture Over Pork. Cover Slow Cooker; Cook On Low Until Pork Is Tender And Liquids Have Formed A Sauce; 7 To 8 Hours.