Wash and dry the okra completely
Trim the ends and slice the okra into thin pieces
Heat oil in a pan over medium heat
Add mustard seeds or cumin seeds if desired
Add chopped onions and sauté until light golden
Add green chilies and curry leaves if using
Add the sliced okra
Sprinkle salt, turmeric, chili powder, and coriander powder
Stir well to coat the okra evenly
Cook on medium to low heat, stirring occasionally
Fry until the okra becomes tender and slightly crisp
Add a little lemon juice if desired
Serve hot