The natural sugars in flowering and fruiting brassicas, such as brussels sprouts, cauliflower and broccoli, can be coaxed out with roasting, stir-frying or grilling. This high-heat cooking is a much better option than boiling, which runs the risk of breaking down the cell membranes and releasing an unpleasant sulphurous smell.
Trim and halve brussels sprouts, drop into a pot of boiling water and cook for 3 minutes. Drain, cool under cold water and drain again.
Heat butter in a large frying pan and cook bacon over a medium heat until fat starts to run (about 5 minutes). Add shallots or onion and cook for about 4 minutes. Add brussels sprouts and stir-fry over high heat until tender and starting to caramelise (about 5 minutes). Season, drizzle with lemon juice, sprinkle with parsley and serve hot.