In a small saucepan bring the cream, milk, herbs and garlic to the boil. Remove from the heat and allow the flavours to infuse.
Peel the potatoes and and cut into large chunks. Place the potatoes in a large pan of salted water. Bring to the boil and then reduce to a simmer until the potatoes are completetly cooked. Drain and then mash the potatoes with a potato masher or ricer.
Pass the milk and cream through a sieve and add gradually to the potatoes. Stir with a large spoon until the mash is the right consistency.
Check the seasoning and keep to one side.
Preheat the oven to 190c.
For the crust:
Pick the leaves from the parsley. Finely chop the garlic.
Place these ingredients in a food processor with the bread, seasoning and olive oil and blitz until you have a fine breadcrumb consistency.
Score the fat on the lamb rumps in a criss cross pattern.
Heat a frying pan with some sunflower oil.
Season the lamb with salt and pepper and colour each side of the lamb until golden brown.
Brush the fat side of the lamb with the mustard and then sprinkle on the breadcrumbs. Pat down to make sure it has stuck.
Transfer to the oven and cook for 15 minutes.
Allow to rest for 5 minutes before serving.
Whilst the lamb is cooking, prepare the dressing and the beans.
Chop the black olives until almost pureed.
Finely dice the chilli and the garlic.
Pick the leaves form the coriander and the mint and roughly chop.
In a bowl mix these ingredients with the olive oil, cumin and capers.
Add a pinch of salt and a squeeze of lemon.
For the beans: Top and tail the beans. Bring a pan of water to the boil and add a generous amount of salt. Cook the beans for 3 minutes in the rapidly boiling water and then drain. Season with salt and pepper and serve with a knob of butter.
Re-heat the mashed potatoes.
Slice the rump into 5 slices. Season each slice with salt and pepper.
Serve with a neat pile of green beans and a large spoon of mashed potatoes. Finish with a drizzle of the black olive dressing.
«Vary the flavours in this dish by changing the herbs in the crumble and the dressing.»