Preheat the oven to 425°F (220°C). Line a large rimmed sheet pan with parchment or lightly oil it. High heat ensures crisp skin and caramelized edges.
Prep the potatoes and aromatics. Halve baby potatoes so they cook evenly.
Toss them on the pan with red onion wedges and smashed garlic. Add 2 tablespoons olive oil, 1 teaspoon salt, 1/2 teaspoon pepper, half the paprika, and half the dried herbs. Mix and spread into a single layer.
Season the chicken. Pat the chicken thighs very dry with paper towels.
In a small bowl, combine remaining 1 tablespoon olive oil, melted butter, lemon zest, honey or maple, remaining paprika, dried herbs, red pepper flakes, and 1 teaspoon salt. Rub this mixture all over the chicken, especially under the skin where possible.
Nestle and add moisture. Place the chicken thighs skin-side up among the potatoes. Tuck in a few fresh rosemary and thyme sprigs.
Scatter the lemon wedges around. If using, drizzle 1/4 cup chicken broth or white wine onto the pan (not over the skin).
Roast for 35–45 minutes. Bake until the chicken skin is deeply golden and crisp and the potatoes are tender. The chicken is done when it reaches 165°F (74°C) at the thickest part, not touching bone.
Optional broil for extra crispness. If you want even more color, broil on high for 2–3 minutes.
Watch closely.
Finish and serve. Squeeze the roasted lemon over everything. Sprinkle with sea salt flakes and a few fresh herb leaves. Serve hot right from the pan.