Spread the peppers and garlic on an oven tray lined with baking paper.
Bake for approx. 30 mins. in the centre of an oven preheated to 220°C. Remove and let stand for approx. 10 mins., covered with a damp cloth. Peel and deseed the peppers and cut into pieces. Peel the garlic cloves and put half of them into a bowl with the peppers. Add the oil and balsamic, season and mix. Divide the pepper and garlic mixture onto the slices of bread and sprinkle the thyme and Fleur de Sel on top.