Heat oven to 350°F. In 4-quart Dutch oven, heat oil over medium-high heat. Add beef in batches; cook and stir until browned. With slotted spoon, remove beef to bowl; sprinkle with salt and pepper.
When all beef is browned and removed from Dutch oven, add carrots and onion to drippings. Cook and stir over medium-high heat 3 to 4 minutes, scraping up browned bits. Sprinkle with flour; stir to mix well. Stir in beef and remaining beef mixture ingredients. Pour into ungreased 13x9-inch (3-quart) glass baking dish.
Cover dish with foil. Bake about 1 hour 30 minutes or until beef is tender and sauce is thickened. Remove from oven; stir. Increase oven temperature to 375°F.
Place pretzels in 1-gallon resealable food-storage plastic bag; crush with rolling pin to make about 3/4 cup. Separate dough into 10 biscuits; cut each into 4 pieces. Brush mustard over dough pieces. Drop handful of dough pieces at a time into bag; shake to coat. Place biscuit pieces evenly on beef mixture, leaving space between pieces.
Bake uncovered 14 to 18 minutes longer or until biscuits are golden brown.