In 10-inch skillet, heat oil over medium heat. Cook bell pepper and onion in oil 8 to 10 minutes, stirring occasionally, until vegetables are tender. Remove from heat; refrigerate vegetables about 10 minutes or until cool.
Meanwhile, in small bowl, mix cream cheese, mayonnaise and steak sauce until smooth.
On microwavable plate, stack tortillas. Cover with microwavable plastic wrap, folding back one edge 1/4 inch to vent steam. Microwave on High 30 seconds.
Spread cream cheese mixture over each tortilla to within 1/4 inch of edge. Place equal amounts of roast beef and vegetables on each tortilla. Sprinkle with cheese. Roll up each tortilla tightly. Cut each roll into 8 pieces; secure with cocktail toothpick.