Rinse the okra, pat it dry with paper towels, trim the ends, and slice into 3/4 inch lengths.
Place the garlic, chilli and 4 tablespoons water into an electric blender and blend until a smooth paste forms.
Transfer the paste to a small bowl and add the ground cumin, coriander and turmerc and mix well.
Heat the vegetable oil in a 9-inch skillet, then add the whole cumin seeds. Once they sizzle (take care, as they easily burn), reduce the heat and pour in the spice mixture from the small bowl. Saute and for about a minute.
Add the okra, salt, sugar, lemon juice and 5 tablespoons water. Stir to mix and bring to a gently simmer. Cover and simmer over low heat until okra is tender, around 10 minutes, adding a splash more water if necessary.