Rinse the lentils under cold water. Dice your onion, carrots, and celery, and slice the mushrooms. Mince the garlic.

In a large pot, heat the olive oil over medium heat. Add the diced onion, carrots, and celery. Sauté for about 5–7 minutes, or until the vegetables start to soften and the onion becomes translucent.

Stir in the minced garlic and sliced mushrooms. Cook for another 5 minutes, allowing the mushrooms to release their moisture and become tender.

Pour in the rinsed lentils, diced tomatoes (with juices), vegetable broth, thyme, rosemary, salt, and pepper. Stir well to combine.

Bring the mixture to a boil over high heat. Once boiling, reduce the heat to low and cover the pot. Allow the stew to simmer for about 30–35 minutes, or until the lentils are tender.

Taste and adjust seasoning if necessary. If the stew is too thick, add a bit more broth or water until the desired consistency is reached.

Ladle the stew into bowls and serve hot, topped with your choice of fresh herbs or a drizzle of olive oil.