Heat the olive oil in a large dutch oven or stock pot over medium heat.
Add the onion, carrot and celery cooking until softened, approximately 5 minutes.
Stir in the garlic and ginger. Cook for an additional minute until fragrant.
Add the apples, bay leaf, curry powder, cumin, paprika, cinnamon, turmeric, cardamon, black pepper and thyme. Cook for 2 more minutes, stirring to prevent scorching.
Stir in the lentils, chicken and chicken broth. Bring to a boil and simmer for 10-15 minutes until the lentils are tender.
Add the coconut milk and cook for 2-3 more minutes.
Season with salt and pepper, to taste.
Notes
Mulligatawny soup can be made up to 2 days in advance. Store in an airtight container in the refrigerator and reheat on the stovetop or in the microwave.