Peel and finely dice the onion and garlic and slice the mushrooms, first removing their stem and brushing off any dirt.
Heat about a tablespoon of olive oil in a large pan over medium to high heat and add in the onion. Using a wooden spoon to prevent the onion from sticking, cook the onion down until translucent. Add in the garlic and the mushrooms and continue to cook until the mushrooms have reduced in size.
Add in the tomato paste, salt, oregano and basil and mix through until combined. Add in the wine stirring to combine and then let cook down for about 5 minutes, until it starts to darken in colour.
Add in the can of tomatoes, vegetable stock and can of brown lentils. Mix through, bring to the boil and then reduce to a simmer for about 20-30 minutes, stirring occasionally to ensure it doesn’t stick to the bottom of the pan. Taste and season with salt and pepper.
While the sauce is simmering, bring a large pot of water to the boil and cook the spaghetti according to package directions.
To serve mix through a little of the bolognese sauce with the drained spaghetti and serve into bowls with a little more sauce on top.