Cook bacon in a large Dutch oven over medium-high until crisp, about 8 minutes. Transfer bacon to a plate lined with paper towels, reserving 2 tablespoons drippings in Dutch oven.
Add carrots and onion to drippings in Dutch oven; cook, stirring often, until beginning to soften, 4 to 6 minutes. Add garlic; cook, stirring occasionally, 1 minute. Add beer; cook about 5 minutes, stirring and scraping to loosen browned bits from bottom of Dutch oven.
Stir in flour; cook, stirring constantly, until mixture is thickened and beginning to brown, 5 minutes. Whisk in broth, salt, and pepper; bring to a boil, whisking constantly. Reduce heat to medium-low, and add potatoes; cover and cook until potatoes are tender, about 20 minutes. Stir in Beef, mustard, vinegar, and cooked bacon. Sprinkle with parsley, and serve immediately.