Step 1

Cut chicken breasts in half horizontally. Cover with plastic wrap and pound with a smooth meat mallet or a heavy pan to an even 1/4-inch thickness. Sprinkle with poultry seasoning, 1/4 teaspoon salt and pepper.

Step 2

Preheat oven to 400 degrees F.

Step 3

Heat 1 tablespoon oil in a large skillet over medium-high heat. Add the chicken and cook until browned and no longer pink in the middle, 2 to 4 minutes per side. Transfer to a clean cutting board; cover to keep warm.

Step 4

Add 1 tablespoon oil to the pan. Cook onion and mushrooms over medium heat, stirring occasionally, until light brown, 6 to 8 minutes. Add sherry and cook, stirring, for 1 minute. Stir in broth, Worcestershire and the remaining 1/4 teaspoon salt. Bring to a boil and cook until the liquid is reduced slightly, about 5 minutes.

Step 5

Meanwhile, cut baguette into 4 portions and slice horizontally. Pull out the soft inner bread; brush the insides with the remaining 1 tablespoon oil. Toast on a baking sheet in the oven for about 10 minutes.

Step 6

To serve, strain the liquid from the mushroom mixture for dipping. Slice the chicken into strips. Divide the chicken and mushrooms among the baguette pieces to make 4 sandwiches. Serve with the dip.