Beef Roasting Joint in Chimichurri

Chop the potatoes into 2cm chunks (peeling optional).

Pop the chunks onto a large (lined) baking tray. Drizzle with oil, season with salt and pepper then toss to coat. Spread out in a single layer. When the oven is hot, roast on the top shelf until golden, 25-35 mins. Turn the tray halfway through. TIP: Use two baking trays if necessary.

Meanwhile, trim and peel the grapefruit. Carefully separate each segment from the white membrane with the help of a knife and chop.
Set the segments aside and juice the remaining grapefruit.

Drain the sweetcorn in a sieve.

Halve, peel and chop the shallot into small pieces.

Halve the chilli and discard the core and seeds. Finely chop.

Peel and grate the garlic (or use a garlic press).

Finely chop the parsley (stalks and all).

In a bowl toss the chopped grapefruit, half the chilli (use less if you don't like the heat), sweetcorn and shallots. Season to taste with salt and pepper. 

Mix 2 tbsp oil (per 2P) with the juice of grapefruit in a large bowl.
Add the remaining chilli(use less if you don't like spice), chopped parsley and oregano. Add as much garlic as you'd like, tasting as you go to avoid overpowering the drizzle.
Stir to combine and season to taste with salt and pepper.

TIP: Use a blender if you'd like a smoother consistency.