Penne Nicoise

Ingredients

• 1 lb green beans, cut into 1 inch lengths (about 4 cups)
• 1 lb red potatoes, cut into 1 inch pieces (about 3 cups)
• 1 lb penne pasta
• 2 tablespoons olive oil
• 1 medium yellow onion, thinly sliced
• 2 garlic cloves, minced
• 1 lb plum tomato, ripe, chopped (about 3 cups)
• 1 cup kalamata olive, pitted and chopped
• 2 tablespoons balsamic vinegar
• 1/2 teaspoon fresh ground black pepper
• salt, to taste