
A strong vinegar, like malt or sherry, gives this baked chicken recipe a pucker factor reminiscent of salt-and-vinegar chips. Everything cooks on one pan, making this chicken sheet-pan dinner perfect for weeknights when you want big results for little effort (so, pretty much every weeknight!).
Preheat oven to 450 degrees F.
Cut chicken breasts into 4 equal portions. Brush with 1 tablespoon oil and sprinkle with 1/4 teaspoon each salt and pepper. Toss Brussels sprouts and onions in a large bowl with the remaining 2 tablespoons oil and 1/4 teaspoon each salt and pepper. Arrange the vegetables and the chicken in a single layer on a rimmed baking sheet.
Roast until an instant-read thermometer inserted in the thickest part of a breast without touching bone registers 160 degrees F and the vegetables are tender, 20 to 25 minutes.
Meanwhile, mix vinegar, dill, garlic powder, onion powder, sugar and the remaining 1/2 teaspoon salt in a small microwave-safe bowl. Microwave on High until the salt and sugar dissolve, about 30 seconds.
Drizzle the vinegar mixture over the chicken and vegetables and roast for 5 minutes more. Transfer the chicken to a serving platter and stir the vegetables on the pan. Serve the vegetables with the chicken.