Wash mushrooms and pat dry with a paper towel.

Gently remove mushroom stems.

In a bowl, toss mushrooms with freshly squeezed lemon juice.

Drain the mushrooms.

Add melted butter to the mushrooms and toss to coat.

In a separate small bowl, beat the egg.

Add crumbled Stilton cheese to the beaten egg and mix well.

Spoon the cheese mixture into the mushroom caps, dividing it equally.

Broil the mushroom caps 8 to 10 inches from the heat source for 5 to 6 minutes, or until golden brown.

Remove the broiled mushroom caps from the oven.

Use tongs to transfer the mushrooms to a serving platter.

Serve the Stilton-stuffed mushrooms hot.