Heat olive oil over medium heat in a large sautee pan. Add okra, toss to coat, and cook for 3-5 minutes. Add chopped onion and garlic and cook for an additional 3 minutes, until onion starts to soften. Add tomatoes, tomato paste, lemon juice, sugar, and spices and simmer for 30 minutes, stirring occasionally. If mixture starts to look dry, add water a few tablespoons at a time. Serve hot over rice.