tangy rhubarb lentil soup

While searching for a non-dessert rhubarb recipe, we stumbled on this recipe on Epicurious last spring.  We’ve made it on multiple occaisions, so it qualifies to be preserved here on the blog.   As you might be able to tell from the few recipes we’ve posted, we make a lot of soups.  In the last couple years we got a soup thermos, which makes soup, along with some tasty bread, a great option even for hiking lunches or other picnics.

• 3 rainbow chard leaves
• 2 Tbs unsalted butter
• 2 tsp brown mustard seeds
• 1 tsp cumin seeds
• 1 tsp coriander seeds
• 1 tsp ginger (?)
• 2 tsp minced garlic
• 1/4 tsp turmeric
• 1/4 tsp cardamom
• 1 medium onion, cut into 1/2 inch dice
• 3/4 lb. rhubarb (about 2 1/2 cups)
• 3/4 cup French green lentils, rinsed and drained
• 1 Tbs packed brown sugar; more to taste
• 6 Tbs whole milk greek yogurt
• 3 Tbs chopped fresh cilantro
• Kosher salt

1. Coarsely chop chard leaves and slice stems 1/2 inch thick and keep the leaves and stems separate.  Dice the onion.  Chop up the rhubarb.
2. Heat the oil in a 4 to 5 quart heavy duty pot over med-high heat. Add the mustard seeds, cumin and coriander seeds, stir to coat, and then cook until the mustard seeds begin to pop, about 1 min.
3. Turn the heat down to med low and stir in the ginger, garlic, turmeric, and cardomom. Cook, stirring, until fragrant, about 2 min.
4. Add the chard stems and onion and cook, stirring occasionally, until the onion is translucent, about 5 min.
5. Add the rhubarb, lentils, brown sugar, 2 tsp salt and 5 cups of water. Bring to a boil and then simmer for 30 minutes.
6. Add the chard leaves. Continue to simmer until the lentils are tender but not falling apart, about 5 minutes more. Season to taste with salt and brown sugar.
7. Immersion blend as desired.  Serve topped with a dollop of greek yogurt and the cilantro.