Place the lentils, bay leaf, and water in a small saucepan over high heat and bring to a boil. Once boiling, reduce heat to low, cover and let simmer for 15 minutes or until lentils are cooked through, adding more water as needed.

Meanwhile, cook the sweet potato noodles. Heat half of the olive oil in a large skillet over medium-high heat. Once oil is shimmering, add the sweet potato noodles and season with garlic powder, salt, and pepper. Cook, tossing occasionally, until cooked through and al dente, about 7 minutes. When done, transfer noodles to a plate and tent with foil to keep warm.

Place the skillet back over medium-high heat and add the remaining olive oil. Once oil is shimmering, add the onions, garlic, celery, and carrots and cook for 5 minutes until vegetables soften. Add the brussels sprouts and cook until browned, about 5 minutes. Add the lentils and tomato sauce and let cook for 5 more minutes, letting flavors mend together.

Divide the sweet potato noodles into bowls and top with equal amounts of the ragu. Garnish with parsley and cheese (if desired.)