Place the dried porcini mushrooms in a medium bowl, add enough hot water to cover and let soak for 20 minutes. Remove the reconstituted mushrooms from the water and squeeze them over the bowl.

Line a strainer with a few layers of cheesecloth, then strain the mushrooms soaking water, reserving ½ cup. Rinse the reconstituted mushrooms.

In a large saucepan over medium heat, melt the butter. Add the shallots and cook, stirring, until softened, about 3 minutes. Add the fresh mushrooms and garlic and cook, stirring, until the mushrooms have softened, about 5 minutes.

Add the salt and the reconstituted mushrooms and cook, stirring, for 1 to 2 minutes, then add the flour and cook, stirring, until combined, about 1 minute. Whisk in the broth, the reserved mushroom soaking liquid and milk. Bring to a boil, stirring constantly, then reduce the heat to low and cook, stirring, until smooth and thick, 10 to 15 minutes; there should be no lingering raw flour taste.

Add the chicken and peas, stir to combine and just heat through.

Shortly before serving, in a small bowl, beat the egg yolks with the cream until combined. Transfer ½ cup of the sauce from the saucepan into the mixture and quickly whisk them together; when it is incorporated, add the egg mixture to the saucepan. Cook, being careful not to let the sauce get too hot or start to simmer (or the eggs might curdle), about 5 minutes.

Add the ¼ teaspoon of pepper, the sherry, tarragon and parsley. Taste, and adjust seasonings.

NOTE: To poach the chicken on the stovetop, cut the chicken in half crosswise, depending on how large the pieces are. In a medium saucepan over medium heat, add the chicken, cover with lightly salted water and a couple of bay leaves, if desired. Stir once or twice and slowly bring to barely a simmer — do not let the water come to a boil. Reduce the heat to medium-low, partially cover and gently cook for about 15 to 20 minutes, or until an instant-read thermometer reads 165 degrees when inserted into the thickest part of the chicken.