Banana-green Mango Chutney

• 1 onion (yellow)
• 1 unripe mango
• 290 gr ripe bananas (very)
• 240 ml vinegar (white)
• 240 ml orange juice (fresh)
• 110 gr dark brown sugar
• 85 gr raisins
• 30 ml peanut oil
• 16 gr ginger (grated fresh)
• 8 gr serrano (finely chopped fresh)