Heat the olive oil in a large heavy-bottomed pot over medium heat until it shimmers and begins to smell fragrant.
Add the chopped onion and sauté until translucent, about 5 minutes, stirring occasionally. The onion should become soft and start to turn golden around the edges.
Stir in the minced garlic and turmeric, cooking for about 30 seconds until the mixture is fragrant and bright yellow, being careful not to burn the garlic.
Add the chopped carrots and cook for another 3-4 minutes, stirring so they start to soften and release their sweet aroma.
Pour in the vegetable broth and add the rinsed red lentils, stirring to combine. Bring the mixture to a gentle simmer.
Reduce the heat to low, cover the pot, and let it simmer for about 20-25 minutes until the lentils are tender and the soup has thickened, with the carrots fully soft.
Uncover the pot and stir. If desired, use an immersion blender to puree part of the soup for a creamier texture, leaving some chunks for contrast.
Taste and season with salt and pepper, then squeeze in fresh lemon juice for brightness. Stir well to incorporate.
Serve hot in bowls, garnished with chopped herbs and a drizzle of olive oil for an extra layer of flavor.
