Transfer the blended mixture back to the pot and stir to combine. Add the lime juice and season to taste with salt (I usually add ½ teaspoon) and pepper. If you would like to temper the flavor and make the mixture even more creamy, stir in a splash of half-and-half or coconut milk, to taste.
Serve in bowls, with chopped cilantro and a lime wedge on top. If desired, serve rice or naan on the side. Leftovers keep well, refrigerated, for up to 5 days.
Remove the bay leaf. Transfer 2 cups of the mixture (make sure to get some liquid with the lentils) to a blender. Securely fasten the lid. Blend until smooth, about 1 minute, being careful to avoid the hot steam rising from the blender lid.
In a large pot or Dutch oven over medium-high heat, warm the oil until shimmering. Add the onion, garlic, ginger and jalapeño, and cook until softened, stirring occasionally, about 4 to 6 minutes.
Stir in the garam masala, cumin, coriander and salt. Season generously with black pepper. Cook, while stirring, for 1 minute.
Add the tomatoes and cook for 1 more minute, while stirring. Add the lentils, kidney beans, water and bay leaf. Raise the heat to medium-high and bring the mixture to a simmer. Reduce the heat to medium-low and simmer until the lentils are nice and tender, stirring occasionally, about 35 minutes.