Toasted Blue Cheese and Caramelized Onion Sandwiches

Why I Love This Recipe
(Bon Appetit)
Ingredients You'll Need
2 T olive oil
2 L white onions, thinly sliced
2 T packed brown sugar
2 T rice vinegar
2 T chopped golden raisins
8 (5.5"x3.5") slices rustic country bread, such as walnut, pecan, or walnut-raisin
2 (6 oz) wedges soft blue cheese
4 T (1/2 stick) butter, room temp
Directions
Heat oil in heavy large skillet over med heat. Add onions and saute until just beginning to color, stirring often, about 20 minutes. Sprinkle sugar over and saute until onions are deep golden brown and very soft, stirring occasionally, about 25 minutes longer. Remove from heat. Mix in vinegar and raisins. Season to taste with salt and pepper (Can be prepared and refrigerated 3 days ahead.)
Arrange 4 bread slices on work surface. Top with cheese, dividing equally. Top each with 1/4 of caramelized onions. Top wtih remaining bread slices to form 4 sandwiches. Spread 2 T butter over tops of sandwiches.
Heat heavy large skillet over med heat. Add sandwiches, buttered side down. Spread remaining 2 T butter over tops of bread. Cover partially and cook about 3 minutes. Turn sandwiches over and cook 3 minutes more. Cut each sandwich into 6 wedges.