Heat the coconut oil in a large pot over medium heat. Add the diced onion and cook for 3 minutes until it softens.
Stir in the minced garlic, grated ginger, and ground turmeric. Cook for 1 minute until the spices smell fragrant.
Add the rinsed red lentils, vegetable broth, and diced carrots. Bring the mixture to a boil, then lower the heat and simmer for 15 minutes.
Stir in the fresh spinach, salt, and black pepper. Cook for 2 more minutes until the spinach wilts.
Remove the pot from the heat and stir in the lemon juice. Taste and adjust salt if needed before serving.