Grilled Portabello Mushroom Sandwich

• 2 clove garlic (minced)
• 2 portabello mushrooms
• 2 onion rolls split
• 1 bell pepper (red roasted)
• 30 ml lemon juice
• 30 ml mayonnaise
• 30 ml olive oil
• 30 ml rice wine vinegar
• 10 ml balsamic vinegar
• 4 gr oregano (dried)