Warmth oven to 425°F. On rimmed baking sheet, throw onions, squash and fennel with 1 tablespoon oil, thyme and 1/4 teaspoon every salt and pepper; cook dinner quarter-hour.
In the intervening time, warmth staying 2 teaspoons oil in medium skillet on medium. Season hen with 1/4 teaspoon every salt and pepper and cook dinner, pores and skin facet down, till profound good brown, 8 to 10 minutes. Flip and cook dinner 3 minutes extra.
Settle hen amongst veggies and meal till hen is cooked by way of, 15 to 18 minutes. Transfer hen to slicing board; let relaxation at least 5 minutes.
In the intervening time, hold simmering greens till ready to serve, round 5 minutes. Lower portion of hen and current with 33% of greens. Refrigerate additional hen and greens for lunch the next day.
