Heat oven to 400 F. Lightly grease a baking sheet.
In a medium bowl, combine the trimmed green beans, tomatoes, garlic, oil, basil, oregano, onion powder, salt and pepper; mix until beans are evenly coated with olive oil and seasoning.
Place the green beans on the baking sheet, making sure to spread out evenly. Roast in the oven for 10 to 15 minutes, stirring after 10 minutes.