Irish Lamb Stew

Name: Irish Lamb Stew
Prep time: 10 min
Cook time: 2 h
Total time: 2 h 10 min
Cuisine: British
Ingredients: ½ cup all-purpose flour; 2 tsp. kosher salt, divided; ½ tsp. black pepper; 2 lbs. lamb stew meat*; 3 Tbsp. vegetable oil; 1 yellow onion, diced; 3 cloves garlic, minced; 2 Tbsp. tomato paste; 1 tsp. chopped fresh rosemary, plus more for garnish; 1 tsp. chopped fresh thyme; 2 cups Irish stout such as Guinness; 1 cup beef or chicken broth or water; 1 bunch carrots with their tops on, peeled and cut into 2-inch pieces; 1 and ½ lbs. waxy potatoes, such as Yukon Gold, peeled and cut into 2-inch pieces; 1 cup peas, fresh or frozen