How to Make It
Preheat the oven to 400°F.
Combine the lemon juice, mustard, garlic, pepper, and salt in a small bowl. Slowly whisk in the oil until emulsified. Coat the chicken with the dressing.
Heat a small nonstick skillet over medium-high. Cook the chicken until browned, about 3 minutes per side. Place the chicken on a baking sheet lined with foil.
Roast at 400°F until a thermometer inserted into the thickest part of the chicken registers 165°F, about 5 to 6 minutes. Let rest 5 minutes. Reserve one breast for Day 2 Lunch.