This is slightly adapted from a Mark Bittman recipe published in the New York Times. It is the only savory rhubarb recipe I've seen (not that I have hunted exhaustively). The rhubarb lends a lovely sour note to the curry, something that might otherwise be achieved with keffir lime leaves. I thought this was fantastic, but my husband didn't like it that well, alas. Try it for yourself and see what you think. Serve this over brown rice.
3 cups rhubarb pieces (1-inch lengths), peeled first
1 1/2 cups red lentils
1/4 tsp cardamom
3 whole cloves
1-2 whole dried chili peppers
1 1/2 Tbsp mustard seeds
3 Tbsp minced fresh ginger
6-8 cloves garlic, minced
Salt to taste
Plenty of coarsely ground black pepper
Combine all ingredients in a large saucepan and add water to cover everything by about 1 inch. Bring to a boil, then simmer over low heat until the lentils and rhubarb are very soft. Remove the chili peppers and cloves (if you can find them). Stir the dal quite a bit so that the rhubarb and lentils both sort of disintegrate.