A full-bodied white with its floral notes and crisp acidity is a great foil to the intense mustard aroma.
Wash chicken breast and pat dry. Add a portion of the whole grain mustard and olive oil to a large bowl and stir to combine. Season with salt and pepper. Toss chicken breast in the mustard mixture, transfer to a plate, and let marinate for at least 30 min.
Add Dijon mustard, remaining whole grain mustard, honey, and vegetable stock to a small bowl. Stir to combine and season with salt.
Slowly heat remaining olive oil in a stainless steel pan set over medium heat. Once pre-heated, transfer chicken breast to the pan and sear for approx. 2 – 3 min. The chicken may initially stick to the bottom of the pan, but after 2 – 3 min., the chicken can be lifted easily. Flip and sear the other side for another 3 min.
Add honey mustard sauce to the pan and top with rosemary. Reduce heat and simmer chicken in sauce for approx. 5 – 7 min. Enjoy with rice!