Combine 2 L water, 4 cups apple cider, kosher salt, and brown sugar in a large pot with thyme and peppercorns. Heat until dissolved. Cool by adding 1 L ice water. Chill the chicken in the brine for 12 to 24 hours.

Remove and pat dry the chicken an hour before roasting, and let it air dry on a rack.

Combine softened butter with chopped thyme, sage, orange zest, salt, and pepper to make the compound butter. Reserve 2 tbsp.

Preheat the oven to 350°F. Slice the onion and orange, prepare the garlic, and toss olive oil in a roasting pan with the veggies and herbs.

Stuff the chicken with the orange half and thyme, slather with compound butter, and tie the legs together.

Pour 1 cup of apple cider into the pan and roast uncovered for 1 hour; cover with foil if it gets too brown.

Halve Gala apples, melt 1 tbsp butter, and place apples next to the chicken, brushing them with melted butter.

Boil remaining cider for 7 to 10 minutes until reduced by half; whisk in maple syrup and compound butter.

Check chicken temperature; glaze when it hits 140°F. Roast until it reaches 165°F and juices run clear.

Strain pan drippings, make a roux with fat and flour, gradually whisk in broth or cider, simmer, and season.

Carve the chicken and arrange apples around, pouring over the gravy.