Heat the oil in a 5-quart covered pan over medium heat. Add the onions and chilies, season with 1 teaspoon salt and cook, stirring occasionally, until the onions begin to caramelize, 8-10 minutes. Add the ginger & garlic and cook, stirring frequently, until very fragrant, 2-3 minutes (lower heat if garlic browns too quickly, do not let it burn). Add the methi leaves, garam masala, chili powder and paprika. Cook, stirring occasionally, until very fragrant, about 1 minute. Add the tomatoes & passata, breaking the tomatoes into pieces with a spoon, and bring to a boil. Reduce the heat and simmer uncovered, stirring occasionally, until the tomatoes are very tender, about 30 minutes.