First make your tomato and basil sauce. This can be done in advance. Get everything chopped and ready.
Heat a large frying pan, add the sunflower oil and the lamb trimmings (not the bones) and brown them on a high heat.
Then add the butter, shallots, mushrooms, garlic, bay leaves, thyme and black pepper and fry until well coloured. Add the tomato puree and stir around until lightly browned.
Add the tomato pulp and reduce, stirring, until the pan is almost dry. Slosh in the wine and deglaze the pan, scraping the bottom with a wooden spoon or heatproof spatula to pick up all the little caramelised pieces. Reduce this down over a high heat until almost all of the liquid has gone.
Add the bones and stir to combine then pour in the stock. Bring the mix to the boil, turn down the heat and simmer very gently until reduced (approx 45 minutes).
Pour the mix through a fine sieve into a clean pan. Add the arrowroot and stir well to combine.
To serve, reheat the sauce so it’s hot but not boiling, add the basil leaves, diced skinned tomato and redcurrant jelly.