Salt
1 cup brown or green lentils, washed and picked over
1 1/2 cups white basmati rice, rinsed well
1/4 cup olive oil
1 large onion, thinly sliced
1/4 cup plain yogurt, preferably whole-milk though low-fat will work, plus additional for serving
2 tablespoons lemon juice, plus additional lemon wedges for serving
1/3 cup water [edited]
2 teaspoons ground cumin
Freshly ground black pepper or red pepper flakes
Chopped fresh flat leaf parsley, cilantro or mint for garnish (optional)