1. Combine lentils, bay leaves, and 6 cups water in large pot. Bring to a boil, cover, and reduce heat to simmer. Cook 30 minutes until tender. Drain and remove bay leaves.
2. Meanwhile, heat large skillet over medium-high heat. Add bacon and onions and cook 10-15 minutes, until fat has rendered a bit and onions are translucent. Add tomatoes, garlic, serrano, and chicken bouillon and cook 15 minutes. Add lentils, 4 cups water, and salt to taste.
3. Simmer at least 15 minutes. Serve with cilantro and tortillas.