In a frying pan, heat the oil over high heat, add the shallot and cook for 30 seconds. Add the mushrooms and cook for 2 minutes or until golden. Pepper to taste.
In a large frying pan, place the 4 bread slices, buttered side down. Spread the cheese over the 4 slices and cook over medium-low heat.
Share the shallot and mushrooms between each slice of bread garnished with cheese.
Then add the roast chicken breast slices and the basil leaves.
Top the sandwiches with the remaining slices of bread, buttered side up. Turn the sandwiches to brown the other side. Serve immediately.
Tip from the chef
For a balanced meal, serve crunchy fresh vegetables and dip alongside this sandwich.