Step 1

Heat vegetable oil in a large pot over medium heat. Cook and stir bacon in hot oil until bacon is browned and crisp, 5 to 7 minutes. Add onion, carrot, celery, and salt; cook and stir until onion is softened and translucent, about 10 minutes. Season with black pepper, cumin, thyme, and cayenne pepper.

Step 2

Pour lentils into bacon mixture and stir to coat completely in rendered bacon fat. Add chicken broth and bay leaf; bring to a simmer, reduce heat to low, and cook, adding more chicken broth as needed, until lentils are tender, 45 minutes to 1 hour.

Step 3

Season with salt, black pepper, and cayenne pepper to taste. Add 3 tablespoons parsley and stir. Ladle soup into bowls, sprinkle remaining parsley over the top and drizzle with extra-virgin olive oil.