4 tablespoons unsalted butter
1 large Spanish onion, chopped
6 cloves garlic, finely chopped
3 tablespoons finely chopped peeled, fresh ginger
1/2 jalapeno, stemmed, seeded, and chopped
1 tablespoon ground coriander
2 teaspoons ground cumin
1 1/2 teaspoons ground turmeric
1/4 cup all-purpose flour
1 3/4 cups red or pink lentils
9 cups chicken broth, homemade or low-sodium canned
3 tablespoons minced fresh coriander (cilantro) leaves, plus 12 sprigs
1 cup unsweetened canned coconut milk
1/4 cup freshly squeezed lemon juice, plus lemon wedges for garnish
2 teaspoons kosher salt
Freshly ground black pepper
If making the soup in advance, adjust its consistency when re-heating with water or broth, since it has a tendency to thicken as it sits.