Preheat oven to 180C. Wrap beetroot in foil, roast until tender (40 minutes-1 hour). Cool, peel, dice and combine in a bowl with grapeseed oil and cider vinegar. Season to taste and set aside.
Meanwhile, combine apple, butter, sugar and a pinch of salt in a saucepan, stir occasionally over very low heat until soft (10-20 minutes). Crush with a fork, season to taste and keep warm.
Increase oven to 190C. Place bacon in a single layer on a baking-paper-lined oven tray, roast until crisp (10-20 minutes). Keep warm.
Heat an ovenproof frying pan over medium-high heat, add olive oil, season quail to taste, add to pan skin-side down, cook until golden (1 minute), turn, roast in oven until cooked through (3-4 mins for medium), cover, set aside.
Divide apple mixture among plates, add quail, spoon over diced beetroot, top with bacon slices and serve immediately.