Heat the olive oil in a large Dutch oven over medium heat.
Add the chopped onion and carrot. Cook, stirring often, for about 5 minutes until softened.
Stir in garlic, cumin, curry powder, and thyme. Cook for 30 seconds to bloom the spices.
Add diced tomatoes and stir well. Let them cook for a few minutes to deepen flavor.
Add lentils, broth, water, salt, red pepper flakes, and black pepper. Bring to a boil.
Reduce heat, partially cover, and simmer for 25–30 minutes until lentils are tender.
Blend 2 cups of the soup until smooth and return to the pot for creaminess.
Stir in chopped greens and cook for 5 more minutes until tender and vibrant.
Turn off the heat and stir in lemon juice. Start with 1 tablespoon and adjust to taste.
Taste and adjust seasonings. Add more salt, pepper, lemon, or red pepper flakes if needed.
Serve hot. Store leftovers in fridge up to 4 days or freeze for several months.