Here's what you'll need:
1/4 cup white wine vinegar
2 Tbs Dijon mustard
2 cloves garlic, chopped
coarse salt and ground pepper
4 boneless, skinless chicken breast halves (6-8 ounces each), split horizontally
1 baguette (about 20 inches), split horizontally, then cut in half
1/4 cup apricot preserves
4 oz thinly sliced deli ham
4 oz white cheddar cheese, grated (1 cup)
So first, heat up your broiler and set the rack 4 inches from heat. Line a rimmed baking sheet with aluminum foil. In a shallow dish or resealable plastic bag, combine vinegar, mustard, garlic, 1 tsp coarse salt and 1/4 tsp black pepper; add chicken and turn to coat. Marinate at room temperature for 10 minutes (or cover and refrigerate in marinade up to 24 hours).
Lift chicken from marinade and place on prepared sheet; broil (without turning) until opaque throughout, 4-6 minutes. Transfer chicken to a work surface; discard pan juices from baking sheet.
Looks good so far! Now, spread each piece of your baguette with some of those apricot preserves and then top 'em off with some chicken.
Layer on the ham and cheese! (I forgot to tell the guy at the deli counter to slice it ultra-thin, I think that would have made a more appealing presentation.)
Pop those babies in the oven under the broiler until the cheese is melted and bubbly. (I would move the rack down one position more to keep the cheese from melting too fast. This will also help your baguette crisp up a little more since it will have more time under the broiler.)