Melt the coconut oil in a large saucepan set over medium heat. Add the onion and celery; increase heat to medium-high and cook, stirring, for 6 to 7 minutes until vegetables are softened.
Add the garlic, garam masala, curry powder, and salt; cook and stir 2 minutes longer.
Add the water, tomatoes with their juices, and lentils to the pan. Increase heat to high and bring to a boil; reduce heat to low, cover, and simmer for 20 to 25 minutes or until lentils are softened. Stir in the lime zest, lime juice, and cilantro.
Serve with additional cilantro and lime wedges, if desired.
Notes
Store: Store the cooled curry in an airtight container in the refrigerator for up to 4 days, or freeze for up to 2 months.