200g/7oz frozen broccoli florets
12 cherry tomatoes, halved
1 onion, finely sliced
500g/1lb 2oz shop-bought gnocchi
1 tsp mustard, Dijon or English
2 tbsp plain flour
salt and freshly ground black pepper
1 tbsp olive oil
 25g/1oz butter
150g/5½oz mature cheddar, coarsely grated
400ml/14fl oz milk, full-fat or semi-skimmed
100g/3½ oz frozen peas