Heat your oven to 180°C/Fan 160°C/Gas 4. Zest and juice the lemon. Peel and slice the garlic. Drain and rinse the chickpeas, saving 4 tbsp. Set aside. Add the rest to a food processor with the garlic, lemon juice and 2 tbsp oil. Blitz to a coarse paste.
With the motor running, gradually pour in 200ml cold water. This will give you a runny houmous. Taste, season and pour into two ovenproof dishes. Cover with foil. Bake for 20 mins. See our tip for making houmous without a processor.
In a dry pan, toast 1 tsp of the cumin seeds for 1 min till fragrant. Add the reserved chickpeas with 1 tsp oil and some salt. Cook on a medium heat till the chickpeas are golden and crispy.
Halve the cucumber and scoop out the watery seeds. Finely dice the cucumber. Quarter the cherry tomatoes. Finely slice the spring greens, discarding any thick cores.
Heat a griddle pan or frying pan till smoking hot. Rub the lamb with a 1 tsp of oil and place in the pan. Cook for 4-7 mins on each side, depending on the thickness of the lamb and how pink you like it. Place on a plate to rest for 10 mins.
In the same pan you used to cook the lamb, add the greens. Add a drizzle more oil if needed. Cook for 3-4 mins till scorched. Place in a bowl and add the lemon zest and a pinch of salt.
Slice the lamb thinly. Remove the houmous from the oven and pile on the cucumber and tomato. Lay the lamb slices on top, drizzling over any juices. Scatter over the warm cumin chickpeas and serve with the sizzled greens.