Balsamic Tomato Butterbeans

Ingredients

• tablespoon olive oil, divided
• large onion, thinly sliced
• vine tomatoes, whole, halved or quartered
• grams olives, finely chopped
• garlic cloves, minced
• tablespoon balsamic vinegar
• can butter beans, drained
• vegetable stock
• tablespoons vegan pesto
• Kosher salt and black pepper, to taste
• Sugar , to taste