In a 4-quart Dutch oven, cook bacon over medium heat, stirring until bacon is crisp. With a slotted spoon, transfer bacon to paper towels; set aside. Reserve bacon drippings in the pan.
In the Dutch oven, cook onions in drippings until tender. Add carrots, celery, red sweet pepper, and garlic. Cook for 5 to 7 minutes or until vegetables are just tender.
Add chicken stock, lentils, water, bay leaves, cumin, and thyme. Bring to boiling over medium-high heat; reduce heat. Cover and simmer for 30 to 45 minutes or until soup is desired consistency, stirring occasionally. Add more stock, if you like.
Remove bay leaves and discard. Add reserved bacon to the soup. Season with freshly ground pepper, if you like. Makes 8 servings.