Mujaddara lentils and rice with Fried Onions and Spiced Yogurt

Name: Mujaddara (lentils and rice) with Fried Onions and Spiced Yogurt
Ingredients: 3/4 cup green lentils; 1/2 teaspoon salt; 1 cup jasmine rice; 3 tablespoons butter divided; 6 tablespoons olive oil divided+ more for caramelizing the onions as needed; 6 cups onions thinly sliced, about 3 medium onions; For the yogurt; 1/2 cup Plain full fat Greek yogurt i used Greek Gods; 1/2 teaspoon cinnamon; 1/2 teaspoon cumin (freshly ground if possible); 1/2 teaspoon coriander freshly ground; 1/2 teaspoon smoked paprika; 3 tablespoons fresh spearmint chopped; Juice and zest of half a lemon; 1/4 teaspoon salt; lemon wedges for serving; parsley to garnish