Potatoes:

1-1/2 lbs Yukon Gold potatoes, peeled, diced
3/4 cup fat free chicken broth
2 tbsp fat free sour cream
salt and pepper
paprika

Filling:

1 lb 95% lean ground beef
1 tsp oil
1 medium onion, diced
1 celery stalk, chopped
2 cloves garlic, diced
8 oz mushrooms, diced
10 oz frozen mixed vegetables (carrots, corn, peas, green beans, baby lima beans)
2 tbsp flour
1 cup fat free beef broth
2 tsp tomato paste
1 tsp Worcestershire sauce
1 tsp freshly chopped rosemary leaves
1 tsp freshly chopped thyme leaves
salt and pepper