Preheat oven to 325°. Sprinkle lamb with 1 teaspoon salt and 1 teaspoon pepper.
In a large Dutch oven, cook bacon over medium heat until crispy and browned. Using a slotted spoon, remove bacon and let drain on paper towels. Reserve drippings in pot.
To pot, add oil. Add lamb, and cook over medium heat until browned on all sides, 2 to 3 minutes per side. Remove from pot.
To pot, add onion, celery, and leeks, cooking until tender and beginning to brown, 7 to 9 minutes. In a small bowl, whisk together 2 cups water and bouillon paste. Pour into pot, scraping browned bits from bottom of pot. Nestle lamb into onion mixture, and cover with lid.
Bake until almost tender through the center, about 1 hour and 45 minutes to 2 hours. Arrange carrots and potatoes around lamb. Sprinkle with remaining ½ teaspoon of salt and remaining ½ teaspoon ground black pepper. Continue baking, covered, until lamb, carrots, and potatoes are fork tender, about 30 minutes more. Sprinkle with bacon, and serve with Lemon-Mint Dressing.
Recipe by Taste of the South at https://tasteofthesouthmagazine.com/slow-cooker-lamb-supper/