Testing - Lamb and Winter Vegetable Stew

https://www.allrecipes.com/recipe/44318/lamb-and-winter-vegetable-stew/

1 - I made it in two ways - first meal was without the flour and cream; the second meal I added flour and cream. The clear winner was the second meal. The first version was ok but we preferred the second. Since the second version was a re-heat of the first meal with added ingredients, I just need to work out the best way of integrating the cream and flour during the usual cooking process.
2 - Yes, the cream sauce addition is a really good one. I added some turnip, which only added to the yum. The onion was still overly firm, so I think I'd like to get it to get all gooey and melty, so I'm going to add it to the meat stewing time.

2 Tbsps vegetable oil
1 lb lamb stew meat, cubed
1 medium onion, thinly sliced
2 cups beef broth
1 cup dry red wine
2 cloves garlic, minced
1 Tbsp chopped fresh thyme
1 Bay leaf
1 tsp salt
1/2 tsp black pepper
1 bay leaf
2 cups peeled, seeded, and sliced butternut squash
2 peeled, sliced carrots
2 peeled, sliced parsnips (cut smaller than carrots - parsnip cook more slowly)
2 peeled, diced sweet potatoes
1 lb turnip or rutabaga, diced
Optional : 1 cup 2 stalks celery, sliced
1/2 cup sour cream
3 Tbsps flour

1. Heat the oil in a large saucepan, and brown the lamb meat on all sides. I continue to brown the meat until any fat has rendered off. Drain fat, and stir in the onion, beef broth and wine. Season with garlic, thyme, salt, pepper, and bay leaf. Bring the mixture to a boil. Reduce heat, cover, and simmer 20 minutes for 1 hour.
2. Mix in the carrots, parsnips, sweet potatoes, celery, and turnip. Bring to a boil, then reduce heat and simmer briskly, uncovered, for 30 minutes, or until the vegetables are tender. 
3. (last time I did this, the liquid boiled down to almost nothing. I added the flour and mixed it in, then added the cream followed by more broth until the desired consistency was achieved - lovely unctuous gravy).
4. SEE POINT 3, ABOVE: In a small bowl, blend the sour cream and flour. Gradually stir in 1/2 cup of the hot stew mixture.
5. Stir the sour cream mixture into the saucepan. Remove the bay leaf, and continue to cook and stir until thickened.