Ham And Cheese Strudels Appetizer ( Paula Deen) - cooking recipe

Ingredients

3 tablespoons butter
3 large sweet onions, thinly sliced
1 tablespoon balsamic vinegar
1 (17 1/3 ounce) box frozen puff pastry sheets, thawed (17.3 oz)
1 egg yolk
1/4 cup mayonnaise
1 tablespoon honey mustard
1 (8 ounce) package mini cubed ham (drained and divided)
1 cup shredded cheddar cheese, divided
1 cup shredded mozzarella cheese, divided

Preparation

In a large skillet, melt butter over medium heat. Add onions; reduce heat to medium- low, cover, and cook for 15 minutes, stirring occasionally.
Uncover and increase heat to medium high.
Continue cooking onions, stirring frequently for 3 to 4 minutes or until onions are caramel colored.
Stir in vinegar, and remove from heat; set aside.
Preheat oven to 400 degrees.
Line 2 baking sheets with parchment paper.
On a lightly floured surface roll 1 sheet puff pastry into a 16x10 inch rectangle.
Place on prepared baking sheet.
Using the times of a fork, prick a 1/4 inch border around the edge of the pastry.
In a small bowl, lightly beat egg yolk; lightly brush over border of pastry. Prick remaining pastry with the tines of a fork in the 1/8 inch intervals.
Repeat procedure with remaining pastry and beaten egg yolk.
Bake for 12 minutes or until golden brown.
In a small bowl combine mayo and mustard. Spread evenly over each baked pastry.
Top each evenly with ham and cheeses.
Spread caramelized onions evenly over cheeses.
Bake for 8 to 10 minutes or until hot and bubbly.
Cut into 2 1/2 inch squares.
Serve immediately.