Caramelized Mushroom And Onion Biscuits

Ingredients

• 1/2 pound cremini mushrooms, sliced
• 1 tablespoon olive oil and 1 tablespoon unsalted butter
• 1 small yellow onion, sliced
• 1 tablespoon olive oil and 1 tablespoon unsalted butter
• 1 tablespoon chopped fresh thyme
• 1 tablespoon balsamic vinegar or balsamic vinegar reduction
• salt and coarse ground black pepper
• 3 cups all-purpose flour
• 2 tablespoons sugar
• 3 teaspoons baking powder
• 1/2 teaspoon baking soda
• 3/4 teaspoon salt
• 1/4 cup vegetable shortening, cold and cut into cubes
• 1/2 cup unsalted butter, cold and cut into cubes
• 1 egg, beaten
• 3/4 cup buttermilk, cold
• 1 egg beaten for egg wash