In a large nonreactive skillet, toast the cumin seeds over moderately high heat, stirring, until fragrant, about 30 seconds. Let cool, then grind in a spice grinder or mortar or finely chop with a knife.
Heat the vegetable oil in the skillet until shimmering. Add the okra and cook over moderately high heat, shaking the pan occasionally, until beginning to brown, about 3 minutes. Add the tomato paste, lemon juice and ground cumin and stir well to coat the okra. Continue cooking until the okra is tender but firm and nicely glazed, about 1 more minute. Season with salt and pepper and serve at once.