In a 12-in. cast-iron or other ovenproof skillet, cook and crumble beef over medium-high heat until no longer pink, 6-8 minutes. Stir in salt and pepper; remove from pan.
In same pan, heat oil over medium-high heat; saute onion, carrots, mushrooms and garlic until onion is tender, 4-6 minutes. Stir in flour and herbs (you can add a dash of red pepper flakes for more spice); cook 1 minute. Stir in wine; bring to a boil. Cook 1 minute, stirring to loosen browned bits from pan. Add beef and broth; return to a boil. Reduce heat; simmer, covered, until flavors are blended, about 30 minutes, stirring occasionally. Remove from heat.
Meanwhile, place potatoes in a large saucepan; add water to cover. Bring to a boil. Reduce heat; cook, uncovered, until tender, 10-12 minutes. Drain; cool slightly.
Preheat broiler. Arrange potatoes over stew, overlapping slightly; brush lightly with oil. Sprinkle with salt and pepper, then cheese. Broil 5-6 in. from heat until potatoes are lightly browned, 6-8 minutes. Let stand 5 minutes. If desired, sprinkle with parsley.