In a large sauce pot over medium-high heat, add the oil and then add the cayenne pepper, cumin, coriander, turmeric, and garam masala. Stir the spices until toasted and fragrant, about 1 minute.
Stir in the onion, garlic, and ginger and cook until softened, 3 to 5 minutes.
Add the apples and lentils and stir to coat in oil and spices. Stir in any optional add-ins.
Add the coconut milk and stock and bring to a boil. Reduce the heat to a simmer,stirring occasionally, until the mixture is thick and mushy, 20 to 25 minutes. If adding in leftover cooked protein such as turkey or chicken, add in now to heat through for an additional 2-3 minutes. Season with salt, pepper, and lemon juice. Serve with garnishes, if desired.
Serve and divide the garnishes among the serving bowls.