Simple Spinach Khichdi

Name: Simple Spinach Khichdi
Ingredients: 1 cup basmati or other long-grain white rice, rinsed; 1 cup red, yellow, or brown lentils, rinsed; 1 Tbsp. vegetable oil; 3 tsp. Diamond Crystal or 1¾ tsp. Morton kosher salt, divided, plus more; 1 jalapeño or serrano chile; 2 10-oz. packages frozen spinach, thawed; 1 cup (packed) cilantro leaves with tender stems; ½ cup (packed) mint leaves; 3 Tbsp. ghee or unsalted butter; 2 tsp. cumin seeds; 1 large onion, finely chopped; 6 garlic cloves, finely chopped; 1 1 piece ginger, peeled, finely chopped; 1 Tbsp. tomato paste; 1 tsp. garam masala; 1 Tbsp. fresh lemon juice