Preheat the oven to broil on high. Add 1 tablespoon of olive oil on two baking sheets and set aside.
Slice your boneless skinless chicken breasts half in thickness, making about 4 thinly sliced chicken breasts.
Cover the boneless skinless chicken breasts evenly in the creamy dijon mustard sauce. Evenly coat the chicken with 2 teaspoon flaky sea salt and ¼ teaspoon black pepper, about 6 pepper grinds.
If using green beans, trim the ends before placing on the sheet pan. For zucchini, cut each zucchini in half and then into large quarters for easy roasting. For the broccoli, cut into florets and place on sheet pan.
Toss the vegetable of your choice with 1 tablespoon of olive oil, 1 teaspoon of flaky sea salt and ¼ teaspoon black pepper, about 6 pepper grinds.
Bake for 15 -20 minutes, flipping the chicken breasts over halfway through the cook. Depending on your veggies, check for doneness around 10-12 minutes to determine if they need to cook longer.
The internal temperature of the chicken should be 165°F. Pull out the chicken to rest for 3 minutes before slicing.