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.
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.
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.
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.
Stir in the garam masala, cumin, coriander and salt. Season generously with black pepper. Cook, while stirring, for 1 minute.