Preheat your oven to 425°F and position a rack in the upper-middle position. Line your large rimmed sheet pan with parchment paper or lightly oil it to prevent sticking and simplify cleanup. While the oven heats, pat your chicken pieces dry with paper towels and season generously with salt and black pepper on both sides.

In a small bowl, whisk together the olive oil, fresh lemon juice, lemon zest, minced garlic, dried oregano, dried thyme, and chicken broth. This bright marinade infuses flavor directly into the cooking process rather than requiring advance marinating time. The combination of acid from lemon and herbaceous notes from oregano and thyme creates the signature flavor profile that makes sheet pan lemon chicken so distinctive.

Arrange chicken pieces skin-side up on your prepared sheet pan, spacing them at least 2 inches apart. Scatter the halved baby potatoes, trimmed green beans, and sliced red onion around the chicken in a single even layer. Pour approximately two-thirds of the lemon marinade over everything, reserving the remaining liquid for basting halfway through roasting.

Roast at 425°F for 15 minutes uncovered. At the 15-minute mark, remove the pan from the oven and stir the vegetables gently, then pour the reserved marinade over everything and return to the oven immediately. This basting step ensures vegetables cook evenly and absorb maximum lemon flavor as the pan dinner continues roasting.

Continue roasting for approximately 10-12 minutes more until the chicken reaches an internal temperature of 165°F when measured at the thickest part with a meat thermometer. The vegetables should be tender and golden at the edges, and the sauce should reduce and concentrate around everything on the pan.

Remove the sheet pan from the oven and let everything rest for 3 minutes before serving. Stir in the fresh chopped parsley and dot the butter across the top while everything is still hot. The butter melts into the pan juices, creating a silky sauce that coats each component beautifully.