Pat the lamb dry and season it with salt and pepper. Toss the cubes with the flour until lightly coated.
Heat the olive oil in a large skillet over medium-high heat. Brown the lamb in batches for 3 to 4 minutes per side, then transfer it to the slow cooker.
Add the onion, carrots, garlic, and mushrooms to the same skillet. Cook for 4 to 5 minutes until the onion softens.
Pour the red wine into the skillet and scrape up any browned bits. Simmer for 2 minutes, then add the beef broth, thyme, rosemary, and bay leaves. Bring the mixture to a quick boil.
Transfer the skillet contents to the slow cooker and stir everything together. Cover and cook on low for 7 to 8 hours.
Remove the bay leaves before serving. Sprinkle with fresh parsley.