Antipasto Grilled Cheese Sandwich - With meat

1 tablespoon olive oil 2 large red onions , peeled, cut in half and thinly sliced 3 tablespoons balsamic vinegar, divided 1/2 lb prosciutto ham , thinly[...]

1 1/2 lbs asparagus , bottoms trimmed and stems peeled (stems about 1/2 inch thick) 4 cups red leaf lettuce , torn 1 cup cherry tomatoes , preferably yellow 3[...]

1 (12 ounce) jar roasted red peppers, rinsed and sliced 1 garlic clove , minced 1/8 teaspoon fresh ground black pepper 1 (6 ounce) jar marinated artichoke[...]