Add onion and garlic to a large non-stick pan on medium-high heat and sauté in a little bit of water for 2-3 minutes. Add carrot, celery and mushrooms and sauté for a further 5 minutes.
Add tomato paste and herbs and mix until well combined.
Then add red lentils, canned tomatoes, tomato sauce and vegetable stock and bring to a boil. Cover, reduce the heat to low and let the bolognese simmer for 15-20 minutes until the lentils are cooked. Season with coconut sugar and salt and pepper to taste.
Cook the brown rice spaghetti according to package instructions and serve up with fresh parsley.