Heat olive oil in a large skillet over medium heat. Add the chicken in an even layer and season with salt and pepper. Cook, stirring occasionally until the chicken is browned, but not all the way cooked through. Remove from the skillet and set aside.
1 tablespoon olive oil, 2 medium chicken breasts
To the skillet, add the butter. Once melted, add the shallots and mushrooms. Cook, stirring occasionally, until the shallots are translucent.
½ cup butter, 1 shallot, 8 ounces white button mushrooms
Stir in the garlic, salt, and pepper. Cook for 30-60 seconds.
1 clove garlic, ½ teaspoon salt, ½ teaspoon black pepper
Add in the flour and cook, stirring, until it has been incorporated and no streaks of dry flour remain.
½ cup all-purpose flour
Slowly stir in the chicken broth, and then the half and half.
2 cups chicken broth, 1 cup half and half
Return the chicken to the pan, bring to a simmer and cook for 5 minutes to let the sauce thicken slightly and the chicken cook through.
Stir in the frozen peas and pimentos. Cook until warmed through, about 5 minutes.
1 cup frozen peas, ⅓ cup pimentos
Serve with biscuits and a garnish of parsley.
8 baked biscuits, 1 tablespoon chopped parsley