Grilled Field Mushrooms on French Toast

• 8 medium onions, peeled and thinly sliced
• 5 g thyme, leaves removed and chopped
• 100 ml

Gently cook the onions and thyme in a covered pan in 30 ml of the vegetable oil until soft.

Season with salt and pepper, add 50 g of the butter and continue to cook without the lid until the onions begin to colour.

Remove from the heat and leave to cool.

Divide the onions between 8 slices of the bread, then press the other slices firmly on top to make 8 sandwiches.