NOTE: The chicken can be prepared the night before and refrigerated. Let it sit on the counter for about 30 minutes before cooking.
Prepare: Preheat the oven to 425F and adjust the oven rack to the middle position. Line a sheet pan with aluminum foil or parchment paper. If using aluminum foil, give it a spray with baking spray. Trim asparagus. Mince the garlic and place into a small bowl. Add the vinegar, oil, 1/4 teaspoon salt and 1/8 teaspoon pepper.
Chicken: Pat the chicken breasts dry and season well with salt and pepper. Spread each breast with 1 teaspoon of Dijon mustard. Lay two pieces of Prosciutto on the work surface, overlapping just a little. Place three pieces of cheese down the middle of the prosciutto. Place a chicken breast, mustard side down, on top of the cheese and wrap the prosciutto around the chicken. Place on the sheet pan seam side down.
Vegetables: Pour the vegetable marinade over the asparagus and toss to coat. Place the asparagus on the sheet pan. Put the tomatoes into the bowl and swirl them around to coat them in the remaining marinade. Place them on the sheet pan.
Cook: Roast the chicken in the oven for 20-30 minutes depending on how thick and cold your chicken is. If the asparagus is thin, it may need to be removed before the chicken is done.
Portion: Plate one prosciutto wrapped chicken breast per person and divide the vegetables evenly.