In a large skillet, heat olive oil over medium-high heat. Add chicken, fry for about 3 minutes each side until golden brown. Remove chicken.
In the same skillet, sauté mushrooms for 2 minutes. Add dry white wine, stir on medium-high heat for about 1 minute. Add cream, mustard and tarragon, stir continuously for another 2 minutes until it thickens.
Return chicken to the skillet and cook until no longer pink, about 5 minutes.