Pat the chicken breasts dry with paper towels. If any breasts are very thick (over 1 inch), butterfly them or pound gently to an even thickness of about 3/4 inch so they cook evenly.

Make marinade

Mince the garlic. In a medium bowl combine olive oil, lemon juice, minced garlic, Dijon mustard, honey, chopped fresh rosemary (or crushed dried), smoked paprika, kosher salt, and black pepper. Whisk until emulsified.

Marinate

Place the chicken breasts in a resealable plastic bag or a shallow dish. Pour the marinade over the chicken, massaging to coat all pieces. Refrigerate for at least 30 minutes and up to 4 hours. (Do not exceed 8 hours for best texture.)

Grilling

Preheat grill

Preheat an outdoor grill to medium-high (about 400°F / 200°C). If using a stovetop grill pan or cast-iron skillet, place it over medium-high heat and preheat for 5–7 minutes until very hot. Oil the grate or pan lightly with 1 tsp olive oil to prevent sticking.

Grill chicken

Remove chicken from the marinade and let excess drip off (do not wipe). Place breasts on the hot grill or grill pan. Grill without moving for 4–5 minutes to develop good grill marks. Flip and grill 4–6 minutes more, or until an instant-read thermometer inserted into the thickest part reads 165°F (74°C). Total cook time will vary with thickness (typically 8–12 minutes).

Rest

Transfer grilled chicken to a clean plate and tent loosely with foil. Let rest for 5 minutes to allow juices to redistribute.

To Finish / Serve

Squeeze a lemon wedge over each chicken breast, sprinkle with chopped fresh parsley, and serve hot. Leftover grilled chicken can be sliced and used in salads, sandwiches, or wraps.