Add about 2 tbsp of coconut milk to a large pot over medium heat. When the coconut milk starts bubbling, add in onion, ginger, and garlic and cook 5 minutes, stirring frequently. Add carrots and celery and cook another 2 minutes.
Add curry paste and stir into veggies. Add vegetable broth and coconut milk and bring to a low boil. Add lentils, stir, and reduce heat to simmer. Simmer 15-20 minutes, until lentils are soft.
Add spinach and stir into curry. Cover and let the spinach wilt for a minute. Turn off heat and stir in cilantro. Taste and add salt or soy sauce to taste.
Serve warm over rice, noodles, or with bread!
Notes
*Some curry pastes contain fish, so make sure to check the ingredients before purchasing.