1.Heat The Oil In A 12-Inch Skillet Over Medium-High Heat. Add The Beef In 2 Batches And Cook Until Well Browned On All Sides. 2.Place The Onion And Garlic Into A 5-Quart Slow Cooker. Top With The Beef. Stir The Picante Sauce And Brown Sugar In A Medium Bowl. Pour The Picante Sauce Mixture Over The Beef. 3.Cover And Cook On Low For 8 To 9 Hours Or Until The Beef Is Fork-Tender. Remove The Beef From The Cooker And Keep Warm. 4.Stir The Flour In The Cooker. Increase The Heat To High. Cover And Cook For 10 Minutes Or Until The Mixture Boils And Thickens. Serve The Sauce With The Beef.