Barbecue spare ribs

1) Combine the ketchup, honey, soy sauce, vinegar, purée, salt and stock and pour over the ribs. Leave to marinade for 2-3 hours.
2) Pre heat oven to 220°C, Gas 7 if barbecuing as well fire up your BBQ and bring to a cooking temperature.
3) Place spare ribs in a roasting pan.
4) Cook in preheated oven for 15minutes.
5) Transfer the ribs to a roasting rack. Lower the oven temperature to 190°C, Gas 5, and cook the ribs for a further 30 minutes until browned and cooked through. 

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6) Transfer to BBQ and cook for a further 30 minutes until browned and cooked through. Basting from time to time with marinade.
7) Meanwhile, place the roasting pan over a moderate heat and boil the cooking liquor until reduced to a thick sauce.
8) Serve ribs with sauce poured over.