Peel the garlic and press it through a garlic press. Mix with mayonnaise. Wash the prawns and dab dry. Wash thyme and dab dry, put something aside for garnishing.
Pluck off remaining leaves. Heat the oil in a pan. Fry the prawns for 2-3 minutes. Add thyme at the last minute. Season with salt and pepper and remove. Wash, sort and clean the spinach.
Peel and finely chop the onion. Sauté onion in hot frying fat. Add spinach dripping wet, season with salt and pepper and cover and let it collapse. Season to taste again. Drain.
Toast bread in the toaster until golden brown. Spread with aioli. Spread the spinach and prawns on top. Crumble cheese and sprinkle on top. Place the toast on a baking tray lined with baking paper. Bake in a preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: level 3) for 4-6 minutes until the cheese is lightly browned.
Serve garnished with thyme.