Brine the Chicken: Combine 2 L water, 4 cups cider, salt, brown sugar, thyme, and peppercorns in a large pot. Heat until dissolved, then cool with 1 L ice water. Submerge chicken (breast side down) and refrigerate 12–24 hours.

Prep the Chicken: Remove from brine, pat dry, and air-dry for 1 hour.

Make Compound Butter: Mix butter, chopped thyme, sage, orange zest, salt, and pepper.

Roast: Preheat oven to 350°F. Layer onion, orange slices, garlic, thyme, and sage in a roasting pan with olive oil. Place chicken on a rack above, stuff with orange and thyme, and rub with compound butter. Add 1 cup cider and roast 1 hour.

Add Apples & Glaze: Add halved apples, brush with melted butter, and roast 30–45 minutes. Reduce remaining cider by half, whisk in maple syrup and butter, then glaze chicken twice during the last 20 minutes. Roast until internal temp reaches 165°F.

Make Pan Gravy: Strain pan juices, skim fat, and whisk ¼ cup fat with flour over heat to make a roux. Gradually add 3 cups broth or cider, simmer, and season.

Serve: Carve chicken and serve with roasted apples and pan gravy.