Beans in Oil (Fasulya Pilakisi)

Legumes - White bean - -

• 250 grams / 9 ounces [[white beans|white bean], soaked for at least 1 hour
• 1 large onion, chopped
• 50 milliliters / 1.7 fluid ounces olive oil
• 2 cloves garlic, sliced
• 2 sticks of celery with leaves, diced
• 1 carrot, diced
• 2 tomatoes, skinned and diced
• Salt
• 2 teaspoons sugar