Rinse the lentils under cold water and drain them.
In a large pot, heat the olive oil over medium heat. Add the chopped onion and sauté for 2-3 minutes until it becomes translucent.
Add the minced garlic, diced carrot, diced celery, and diced red bell pepper to the pot. Sauté for another 5 minutes until the vegetables start to soften.
Stir in the canned crushed tomatoes, tomato paste, dried oregano, dried basil, dried thyme, salt, and pepper. Cook for 2-3 minutes, allowing the flavors to meld.
Add the rinsed lentils and vegetable broth (or water) to the pot. Stir well and bring the mixture to a boil.
Reduce the heat to low, cover the pot, and let the lentil bolognese simmer for about 20-25 minutes or until the lentils are tender and the sauce has thickened. Stir occasionally to prevent sticking. If needed, add more broth or water to achieve your desired consistency.
While the lentil bolognese is simmering, cook the whole wheat spaghetti or pasta according to the package instructions until al dente. Drain and set aside.
Taste the lentil bolognese and adjust the seasoning if necessary by adding more salt and pepper.
Serve the lentil bolognese over the cooked pasta. If desired, garnish with grated Parmesan cheese and fresh basil leaves.Enjoy your delicious and nutritious Lentil Bolognese with metric measurements!