Preheat the oven to 160 ° C top and bottom heat. If you use thyme sprigs, wash them, shake them dry and pluck the leaves off.
Brush four hollows of a muffin tin with the oil. Roll out toast slices thinly with a rolling pin. Carefully press each slice into the hollows, brush with a little mustard, line each with a slice of bacon and sprinkle with thyme. Beat an egg in each toast muffin. Bake the muffins in the oven for 25-30 minutes until the egg has set.
Carefully lift the muffins out of the hollow and serve.