Remove the stalks from the mushrooms and peel off the outer skin and discard. Place the mushrooms on the baking sheet.
Mix the cream cheese, dijon, lemon juice and thyme leaves with a pinch of salt and pepper in a small bowl. Combine well.
Using a teaspoon, spoon the mixture into the hollowed out mushrooms - pile it in! Sprinkle over the parmesan and breadcrumbs.
Place the mushrooms into the oven and bake for around 25 minutes until the tops are golden brown and crispy.
Notes
Take the cream cheese out of the fridge about 30 minutes before you are going to make the mushrooms. The cheese will soften and it will be much easier to combine the ingredients.Bake the mushrooms in a lightly oiled tray with a rim so that the juices get caught and don't make a mess of your oven.Don't over crowd your pan with the mushrooms, use two trays if you are making a double batch.You can make these mushrooms several days ahead of time. See the post above for all make ahead options.Nutritional values are an approximation only and based on one of four servings of 3 mushrooms.