I got this recipe from the Food Network and though the users don't rate it highly, with my adjustments, this is a killer dish! I served it with rice, the guacamole salad below and rolls.
2 cups (4 ounces) fresh broccoli florets
1/2 cup (2 ounces) grated Gruyere cheese
1 clove garlic, finely chopped
4 (6 to 8-ounce) boneless skinless chicken breast halves
2 teaspoons olive oil
2 teaspoons chopped fresh thyme
Kosher salt and freshly ground black pepper
1 cup low-fat evaporated milk
1/2 cup low-sodium chicken broth
1/4 cup dry sherry (or white grape juice)
3 teaspoons cornstarch
2 tablespoons grated Parmesan cheese
1 teaspoon Dijon mustard
Preheat the broiler. Mist a shallow rectangular baking dish with cooking spray. Bring a medium pot of salted water to a boil. Add the broccoli and cook until bright green and crisp tender, about 5 minutes. Drain well and run under cold water until cold. Drain well again and squeeze dry in paper towels.
Chop the broccoli and toss in a bowl with the Gruyere and garlic. Pound chicken to an inch thick. Insert a paring knife into the thickest part of each chicken breast to make a 3-inch deep pocket. Stuff each chicken breast with equal amounts of the broccoli mixture. Rub both sides of the chicken breasts with oil and thyme and season with salt and pepper.
Heat a large nonstick skillet over medium-high heat until very hot, about 5 minutes. Put the chicken in the pan and cook until golden brown and just cooked through, about 6 minutes per side. If the chicken begins to brown too quickly, turn the heat down to medium to finish cooking through. Transfer to the baking dish.
Meanwhile, combine the milk and stock in a small pot, season with salt and pepper and bring to a simmer over medium heat. Stir the sherry and cornstarch until smooth and pour, whisking constantly, into the sauce. Cook until just thickened, about 2 minutes. Remove from heat and stir in the Parmesan. Top each chicken breast with 2 tablespoons of sauce and place under the broiler. Broil until lightly browned, 2 to 3 minutes.
Let the chicken rest for 5 minutes and then cut each breast in half on an angle. Whisk the mustard into the remaining sauce and spread a few tablespoons on each plate. Top with a halved chicken breast.