Pull out one sheet of puff pastry and let it thaw. Then roll out slightly and cut into quarters. Put back into freezer.
In a medium sauce pot, melt butter and sauté mushrooms. Pour in Merlot wine and cook alcohol off for 5 minutes over medium heat.
Next toss in meat and vegetables and let simmer together for 5 minutes.
While stew is simmering, combine two tablespoons of beef stock and cornstarch. Mix together and pour into pot along with remaining beef stock. Let mixture cook and sauce thicken about 30 minutes.
Pour mixture evenly into oven safe bowls. Pull out frozen puff pastry sheets and put on top of filled bowls. Bake in oven at 400 °F for 10-15 minutes or until golden brown.