Heat a tablespoon of olive oil in a large heavy-bottomed pot over medium heat. Once shimmering, add the chopped onion and cook, stirring occasionally, until translucent and fragrant, about 5 minutes.
Add the minced garlic and grated fresh turmeric to the pot. Cook for about 1 minute until fragrant, making the mixture sizzle gently and fill your kitchen with earthy aromas.
Stir in the chopped carrots and zucchini, allowing them to soften slightly as they cook for about 5 minutes, their edges beginning to turn tender yet still holding some shape.
Pour in the vegetable broth and add the rinsed red lentils. Bring the mixture to a rolling boil, then reduce the heat to maintain a gentle simmer.
Cover the pot loosely and cook for 20 to 25 minutes, stirring occasionally, until the lentils are soft and breaking down, creating a slightly creamy texture throughout the soup.
Season the soup generously with salt and pepper, tasting and adjusting as needed. Add a teaspoon of ground turmeric if you want a more vibrant color and flavor boost.
Stir in the chopped greens and cook for another 5 minutes until wilted and tender, adding a fresh burst of color and nutrients.
Remove the soup from heat and stir in the lemon juice, brightening the flavors and adding a lively contrast to the earthiness of the turmeric and vegetables.
Finish with a drizzle of olive oil for richness and a touch of salt if needed. Let the soup rest for a few minutes to allow flavors to meld.
Serve the warm, vibrant soup in bowls, garnished with fresh herbs if desired, and enjoy its comforting, nourishing qualities.