Place the sliced okra in a small saucepan, and cover with water. Bring it to a boil over medium-high heat, and reduce the heat.
Let it simmer, uncovered, for 7 to 10 minutes or until the okra is tender. Editor’s Tip: Why boiled okra? If you’re looking to lessen the sliminess, okra is better suited to short, high-heat cooking preparations, like grilling, frying and boiling. Boiling okra for a short amount of time here softens it, so it's only a quick stew with the tomatoes.
Meanwhile, in a large skillet, heat the oil over medium-high heat.
Add the onion and green pepper. Cook the mixture, stirring, until tender, four to seven minutes. Stir in the tomatoes, sugar, flour, salt and pepper. Bring everything to a boil, and cook, stirring, until the tomatoes are tender and juices slightly thickened, three to five minutes.
Drain the boiled okra, and stir it into the tomato mixture. If desired, serve okra and tomatoes over rice.