INGREDIENTS
2 large skinless, boneless chicken breasts (about 1¼ lb. total)
3 Tbsp. Diamond Crystal or 3½ tsp. Morton kosher salt, plus more
1 lemon, halved
2 Tbsp. Dijon mustard
6 Tbsp. extra-virgin olive oil
Freshly ground black pepper
8 oz. green beans, trimmed
1 large head of Bibb lettuce
1 small bunch chives, sliced into (2”-long) pieces
1 cup basil leaves
1 bunch radishes, trimmed, halved, cut into wedges if large
1 cup torn peperoncini
1 avocado, thinly sliced
PREPARATION
Place chicken in a large saucepan and pour in 4 cups cold water to cover; add 3 Tbsp. Diamond Crystal or 3½ tsp. Morton kosher salt. Bring to a gentle boil over medium heat, then immediately turn over chicken with tongs. Cover pot, remove from heat, and let chicken sit until an instant-read thermometer inserted into the thickest part registers 150°F, 5–10 minutes (depending on thickness of breast). Transfer chicken to a cutting board and let rest 10 minutes.
Meanwhile, squeeze lemon halves into a medium bowl. Whisk in mustard, then gradually stream in oil, whisking constantly until dressing is thick and emulsified. Season with salt and pepper.
Using a rolling pin, whack green beans on a cutting board until skins split and insides are softened but not pulverized.
Transfer beans to a medium bowl and drizzle in 2 Tbsp. dressing. Massage beans with your hands to break down further and coat; season with salt.
Separate lettuce leaves; toss in another medium bowl with chives and basil. Arrange on a platter.
Toss radishes, peperoncini, and 1 Tbsp. dressing in the same bowl; season with salt. Slice chicken ¼”–½” thick; season with pepper. Arrange chicken, radish salad, green beans, and avocado on platter with lettuce as desired. Drizzle with more dressing; serve remaining dressing alongside.