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Ingredients:
- 2 teaspoons olive oil
- 1 large white onion, sliced into rings
- salt and black pepper, to taste
- 12 oz leftover garlic lovers roast beef, sliced thin
- 8 oz whole wheat Italian or French bread, cut into 4 pieces
- 4 oz reduced-fat Swiss Cheese or provolone
Directions:
Heat a 10-inch skillet over medium-low heat. Stir in the oil and onions, season with salt and pepper and cook until slightly brown, turning occasionally about 15 to 17 minutes.
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Slice the bread open, place 3 oz of cooked roast beef on each piece and top with 1/4 of the caramelized onions. Top with cheese and place in the broiler for 1 to 2 minutes to melt the cheese, careful not to burn it.
source
http://www.skinnytaste.com