This is the perfect dish for a hot summer day.
Put 1 cup green or brown dried lentils in a pot with three cups water. Bring it to a boil, then lower the heat and simmer until the lentils are done, about thirty minutes. (Note: if you do this with red lentils, they will disintegrate in ten minutes or less, at which point you’ll be well on your way to making daal. Stick to brown, green, or puy lentils if you want to make a salad.)
Dump the lentils into a colander and rinse them with cold water.
Chop up a bunch of vegetables. I try to stick with whatever is in season – sugar snap peas, cucumbers, scallions, and garlic scapes this time of year; tomatoes, cucumbers, green beans, and scallions in mid-summer; tomatoes, cucumbers, carrots, bell peppers and onions in late summer – but you can put in whatever you like. I recommend buying whatever looks good at the farmers market (or harvesting whatever looks good in your garden), and then chopping up enough veggies to make your salad look colorful.
Put the lentils and vegetables in a big bowl or tupperware container, add plenty of vinegar. I like rice vinegar best for this dish, but red wine or cider vinegar would be just fine. I think lemon juice would be good too. I’d start with 1/3 cup vinegar, then add more vinegar to taste. I’d add a little salt at this stage, and you can add a couple tablespoons of olive oil, too, though I usually leave the oil out.
Stick the salad in the fridge to finish cooling and/or marinate – this is one of those dishes that tastes better the second day.