Heat olive oil in a large heavy-bottomed pot over medium heat until it shimmers and starts to ripple.
Add the chopped onion and cook, stirring occasionally, until it becomes translucent and soft, about 5 minutes. You’ll notice a gentle sizzle and a sweet aroma as the onions soften.
Stir in the minced garlic and grated ginger, cooking for about 30 seconds until fragrant. The mixture should become aromatic, filling the kitchen with a warm, spicy scent.
Add the turmeric powder and cumin, stirring constantly for about a minute until the spices are toasted slightly and release their earthy aroma.
Pour in the vegetable broth, then rinse the rinsed lentils and add them to the pot. Bring everything to a gentle boil, watching the mixture bubble steadily.
Add the chopped carrots, stirring them into the simmering broth. Reduce the heat to low and let the soup simmer gently for 25 to 30 minutes, stirring occasionally, until the lentils are tender and the soup thickens slightly.
Check the lentils; they should be soft and breaking down a bit. If they are bursting, reduce the heat to prevent over-mushing.
In the last 5 minutes of cooking, stir in the chopped leafy greens and cook until wilted, about 2-3 minutes. The greens should turn bright and tender.
Remove the pot from heat, then stir in the lemon juice. Taste and season with salt and pepper as needed, adjusting the brightness and saltiness.
Spoon the hot, vibrant yellow soup into bowls, finishing with a drizzle of olive oil and an extra squeeze of lemon if desired. Serve warm and enjoy its cozy, comforting flavor.