Serve up this fiber-rich bean toss with roast chicken or grilled fish.
In a large saucepan, heat oil over medium. Add onion and oregano; season with salt and pepper. Cook, stirring occasionally, until tender, 4 to 5 minutes.
Add beans and tomatoes. Cook, stirring occasionally, until tomatoes are tender, 3 to 4 minutes. Remove from heat, and add lemon juice to taste. Season with salt and pepper.