Wild Mushroom Melt Panini

INGREDIENTS

• 1 tablespoon extra virgin olive oil
• 1 tablespoon unsalted butter
• 1/4 cup thinly sliced shallots
• 2 teaspoons minced garlic
• 2-1/2 cups sliced wild mushrooms, such as shiitake, chanterelle or porcini
• 1 tablespoon balsamic vinegar
• 1 tablespoon chopped fresh parsley
• Coarse salt and black pepper
• 4 tablespoons butter, room temperature
• 8 slices rye bread, sliced from a dense bakery loaf
• 1/2 pound Gruyère or Swiss cheese, sliced