For the Mujaddara

3/4
cups Puy lentils (aka French lentils, the tiny dark brown ones)
1
teaspoon salt, divided
1
cup jasmine rice
2
tablespoons butter
3
tablespoons olive oil
6
cups onions (about 3 medium onions), halved and thinly sliced
For the yogurt

1/2
cup Greek yogurt
1/2
teaspoon cinnamon
1/2
teaspoon cumin (freshly ground, if possible)
1/2
teaspoon coriander (freshly ground)
1/2
teaspoon spicy paprika or aleppo pepper
3
tablespoons chopped fresh mint
Juice and zest of half a lemon
1/4
teaspoon salt