This hot mustard livens up steak, roast beef and cold cuts and works a treat as a dressing for sautéed potatoes.
Put the mustard seeds in a bowl, pour over boiling water to cover them, cover and set aside to soak overnight.
Grind the fennel seeds, salt and pepper to a powder in a spice grinder, then transfer to a large bowl.
Add the kohlrabi and garlic and stir to coat in the spice mixture.
Pour over the vinegar, then stir in the mustard seeds, sugar, honey, lemon juice and lemon thyme until well combined.
Put the mustard in a sterilised jar, seal and store in the fridge for up to a week. Serve with steak, roast beef or cold cuts.
