Baked Onions With Balsamic Vinegar
["6 medium Vidalia or Texas sweet onions, peeled", "1/4 c. plus 1 Tbsp. olive oil", "1 1/2 tsp. Dijon mustard", "2 Tbsp. balsamic vinegar (no substitute)", "1/2 tsp. salt", "1/4 tsp. pepper"]
["Cut off roots and stem ends of onions.", "Using a sharp knife one should make a deep \"X\" on top of each onion, cutting halfway down. Place each onion on a 6 x 6-inch piece of aluminum foil with \"X\" up.", "Bring up corners of each square.", "Top each with 1 teaspoon olive oil.", "Twist foil together tightly to completely enclose onions.", "Place twist up on a large baking sheet.", "Bake 40 minutes at 350\u00b0 until tender."]
["onions", "olive oil", "mustard", "balsamic vinegar", "salt", "pepper"]