Trim the leaves off the radishes and put the leaves to one side for later. Finely slice the radishes and pop them in a bowl. Finely grate the zest off the lemon and set aside. Squeeze the juice from half the lemon over the radishes. Add a pinch of salt and scrunch together. Set aside to pickle a little.

Measure 1 tsp wholegrain mustard into a small bowl and squeeze in the juice from the remaining lemon half. Add the lemon zest and ½ tbsp olive oil. Season with salt and pepper. Whisk together with a fork to make a dressing.

Separate the lettuce leaves and arrange them on two serving plates. Drain and rinse the green lentils. Set aside in the sieve for later.

Heat a large frying pan until smoking hot and add 1 tbsp olive oil. Season the rump steak well with salt and pepper and add to the pan. Fry for 4-5 mins in total, turning occasionally, until slightly browned on all sides. Pop the steak on a board, loosely cover with foil and set aside to rest for 3-4 mins.

Add the lentils and 100ml boiling water to the pan. Bring to the boil, then cover and simmer for 2 mins. While the lentils simmer, roughly chop a handful of the peppery radish leaves (the rest will keep in the fridge for 2-3 days and are great in salads or turned into a pesto).

Stir the mustardy dressing and radish leaves into the lentils. Taste and add a pinch more salt and pepper if you think it needs it.

Spoon the lentils over the lettuce leaves and top with the beef. Spoon over half the pickled radishes and their lemony pickling liquid (see our tip on how to use the leftover radishes). Serve straight away.