Preheat the oven to 375 degrees.
Place the chicken breasts on a sheet pan and rub them with olive oil. Sprinkle generously with salt and pepper. Roast for 35 to 40 minutes, or until cooked through. Set aside until cool enough to handle, then remove the meat from the bones and discard the skin. Cut the chicken into large dice. You will have 4 to 6 cups of cubed chicken.
In a small saucepan, heat the chicken stock and dissolve the bouillon cubes in the stock. In a large pot or Dutch oven, melt the butter and sauté the onions over medium-low heat for 10 to 15 minutes, until translucent. Add the flour and cook over low heat, stirring constantly, for 2 minutes. Add the hot chicken stock to the sauce. Simmer over low heat for 1 more minute, stirring, until thick. Add 2 teaspoons salt, 1/2 teaspoon pepper, and the heavy cream. Add the cubed chicken, carrots, peas, and parsley. Mix well. Place the stew in a 10 x 13 x 2-inch oval or rectangular baking dish. Place the baking dish on a sheet pan lined with parchment or wax paper. Bake for 15 minutes.
Remove the stew from the oven and arrange the biscuits on top of the filling. Brush with egg wash. Bake for another 20 to 30 minutes, until the biscuits are brown and the stew is bubbly, or brush the egg wash on the prepared biscuits and bake according to package instructions, on a separate baking sheet.
Add the chicken stew to shallow bowls. Place the golden biscuits on top. Enjoy!