Heat a large pot over medium heat and add the olive oil, letting it shimmer for about 2 minutes.
Add the chopped onions, carrots, and celery to the pot. Cook, stirring occasionally, until the vegetables soften and release a sweet aroma, about 8 minutes.
Stir in the turmeric and cumin, cooking for another minute until fragrant and the mixture turns a warm yellow color.
Pour in the vegetable broth and add the rinsed lentils. Bring the mixture to a gentle boil, then reduce the heat to low and cover the pot.
Allow the soup to simmer gently for 25-30 minutes, or until the lentils are tender and the vegetables are easily pierced with a fork. You’ll notice the soup thickening and turning a vibrant yellow hue.
Optional: Use an immersion blender to puree part of the soup directly in the pot, creating a creamy, velvety texture while leaving some chunks for texture.
Remove the soup from heat and stir in the freshly squeezed lemon juice to brighten the flavors.
Taste and adjust the seasoning with a pinch of salt or more lemon juice if desired.
Ladle the steaming soup into bowls, garnishing with fresh herbs or a drizzle of olive oil if you like.
Enjoy your comforting, vibrant bowl of turmeric lentil vegetable soup, perfect for grounding and nourishing your day.