Combine beef stock, tomato sauce, thyme, parsley, salt, pepper, and sugar in a bowl, whisk it together and set aside.
Cut lamb roast into about 1-inch pieces. Dice carrots, cut potatoes, mince garlic, and slice onion.
Sear:
Sear chopped lamb pieces in batches until nicely browned. Set seared meat aside in a separate bowl.
Add onion and carrots to the pot and let is sear for a few minutes as well. Stir in minced garlic and cook just until garlic is fragrant.
Add lamb back into the pot. Sprinkle flour over meat and vegetables and mix until all the pieces are evenly coated.
Pour beer in slowly as you scrape the bottom of the pan with a wooden spatula.
Stew:
Add potatoes to the pot, pour in the beef stock mixture, and stir it all to combine. Add bay leaves and lower the heat to low.
Cover with a lid but leave a crack for the steam to escape. Cook for 2 – 2 1/2 hours, stirring once in a while.
Discard bay leaves and serve.
Notes
Gluten Free Notes: To make this recipe gluten free, simply use gluten free all purpose flour! Remaining ingredients should already be gluten free but check the packaging to make sure.Omitting Beer: While beer does add to the overall flavor of the stew, you can omit it or substitute it with a non-alcoholic beer.Using Beef: If you are not a fan of lamb, you can use beef instead. The best beef to use for a stew is chuck roast. It’s inexpensive, tough, and has lots of marbling and connective tissue.