Preparation Position rack in center of oven and preheat to 475°F. Mix first 3 ingredients in medium bowl. Mix in feta, 1/2 cup Parmesan, Jack cheese, and onions. Spread 2 tablespoons cheese mixture onto each bread slice. Top each with 1 tablespoon Parmesan; press to adhere. Place on baking sheet. Sprinkle lightly with salt and pepper. Bake until cheese is golden and bubbly, about 12 minutes. Test-kitchen tip:The cheese mixture is nice to have on hand for parties. It can be frozen for up to 1 month, then thawed and used with bread, crackers, or veggies.
Preparation Position rack in center of oven and preheat to 475°F. Mix first 3 ingredients in medium bowl. Mix in feta, 1/2 cup Parmesan, Jack cheese, and onions. Spread 2 tablespoons cheese mixture onto each bread slice. Top each with 1 tablespoon Parmesan; press to adhere. Place on baking sheet. Sprinkle lightly with salt and pepper. Bake until cheese is golden and bubbly, about 12 minutes. Test-kitchen tip:The cheese mixture is nice to have on hand for parties. It can be frozen for up to 1 month, then thawed and used with bread, crackers, or veggies.