Mackerel croquettes with herby couscous

By Matt Tebbutt From Saturday Kitchen Ingredients For the béchamel 250–300ml/9–10fl oz full-fat milk (or any milk) 1 bay leaf 1 garlic clove 2 thyme sprigs (or dried thyme or any other herb) 30g/1oz unsalted butter 50g/1¾oz plain flour 100g/3½oz strong cheddar, grated (or any hard cheese) 1 …