Season the monkfish with a little salt.
Heat a large frying pan until medium hot, add a knob of the butter and all the oil. Cook the monkfish on each side until just golden – about a minute either side.
Remove the fish and rest on a plate covered in cling film.
Place the red wine, vinegar, sugar, 50ml/2fl oz water and shallot into a saucepan and cook until reduced to a syrup.
Heat a frying pan over a high heat and cook the remaining butter, thyme and whole garlic clove until a nut-brown colour.
Mix the red wine syrup and butter together – there should be double the quantity of butter to red wine – check the seasoning, then remove the garlic clove.
To serve, place the monkfish onto plates then spoon the red wine dressing over the top.