Seeing pictures from the Bach Festival’s dining hall reminded me of this delectable appetizer, willingly shared by the dining hall chef one afternoon.
Marinate a pound of sliced mushrooms in some balsamic vinegar for at least an hour.
Sweat some chopped onions and garlic in a little olive oil. (Sweating is the technical term, I learned, for using low/medium heat to barely cook the onions until they are translucent.)
Add the mushrooms to the onion, and cook until the moisture has evaporated.
Toast some pine nuts.
Crumble some feta, and grate some Parmesan.
Melt some butter.
Thaw some puff pastry, and keep between damp towels as you work.
To assemble: Brush melted butter onto a sheet of pastry, top with another sheet, butter, top with a third sheet and butter. Cut the pastry into 3-4 inch squares. Spoon a little mushroom mixture onto each square, top with a few pine nuts and a little feta. Add just a touch of Parmesan to each mound. Gather the four corners of each square into a loose “packet” to lift it into a lightly oiled mini-muffin cup. (If you don’t have these, pinch the pastry together just above the filling, and give it a slight twist, placing the packets on a cookie sheet.) Bake at 350 until the pastry is golden and the cheese is bubbly.
If the whole idea of puff pastry seems like too much work, try this:
After sweating the onions/garlic, add the mushrooms to the pan and toss to combine. Put the mushroom/onion mixture in a buttered casserole, top with the pine nuts and cheeses, and bake at 350 until the cheese is bubbly. Serve with some good crackers or toasts as an appetizer spread. Or spoon some on a plate as a side dish to a meal. Or eat the stuff straight from the pan with a spoon. (Do not share.)
Experiment with different cheeses and nuts. Play with your food!