Despite their name, red lentils are coral, and they turn yellow when cooked. Here, they are simmered with fragrant Indian spices until they collapse into puree. Nuggets of pumpkin-colored squash and forest green ribbons of mustard greens are stirred in to complete the soup. Look for the lentils in Indian markets. Brown lentils are not a good substitute, as they don’t break down as readily as the red lentils do.
Heat the canola oil in a large pot over moderate heat.
Add the onion, garlic, ginger, turmeric, cumin, and chile
and sauté until the onion is soft, about 10 minutes. Add the
lentils, bay leaf, broth, and water and bring to a simmer,
skimming any surface foam. Cover and adjust the heat to
maintain a gentle simmer. Cook until the lentils are soft,
about 30 minutes.
Season the lentils with salt and pepper. Stir in the
squash. Cover and simmer until the squash is almost
tender but still slightly firm, about 8 minutes. Stir in the
mustard greens, re-cover, and remove the soup from
the heat. Let stand until the mustard greens soften and the
squash is fully cooked, 5 to 10 minutes.
Remove the bay leaf and chile. Taste and adjust the
seasoning. Divide the soup among warmed bowls. Serve
immediately.