Eggplant With Yogurt

• 3 onions
• 2 garlic (cloves)
• 1 eggplant
• 1 ogurt
• 60 ml vegetable oil
• 16 gr ginger (freshly grated)
• 3 gr salt
• 2 gr coriander (ground)
• 2 gr cumin
• 2 gr sugar