Preheat oven to 400°F.
In a large pan over medium heat, heat 2 tbls of
olive oil. Add the diced onions and cook until
golden and soft (about 10-15 minutes). Stir in
salt and add sliced mushrooms. Cook together
until the mushrooms are tender and
caramelized, about 10 minutes.Stir cornstarch
slurry and cook until thickened (approx 2
minutes). Add in butter, garlic, thyme and
balsamic vinegar and cook for another 2
minutes. Remove from heat and set aside.
Remove the puff pastry from the fridge. Cut into
7cm squares. Score 1 ½ cm from the 4 edges of
each square (do not cut right through the
pastry). Spoon mushroom mixture within the
scored areas of each square and top lightly with
Brush edges with egg mixture.
Bake at 400° F for 12-16 minutes or until
Cool on wire rack and garnish with more fresh
thyme and season to taste.
Let cool and enjoy!