Pop the skewers in a bowl of water to soak (this helps stop them burning when you're grilling the kebabs). Heat your oven to 180°C/Fan 160°C/Gas 4.
Scrub the potatoes. Slice them into chips as thick as your fingers. Tip them into a bowl. Add 1 tbsp olive oil and some salt and pepper. Shake to coat the spuds in the oil and seasoning. Spread out on a baking tray. Bake in the oven for 30 mins till golden and cooked through.
Meanwhile, peel and grate or crush the garlic. Finely grate the zest from the lemon. Juice it. Mix the garlic, lemon zest and juice together in a bowl. Spoon ½ out into a separate bowl for the salad dressing and set aside. Add 1 tsp of the dried oregano to the rest of the marinade. Season.
Add the beef to the lemon and oregano marinade. Turn to coat. Pop to one side for 10 mins while you make the chopped salad.
Roughly chop the cherry tomatoes. Halve the cucumber and set one half aside (see our tip for what to do with it). Halve the other half lengthways. Slice into batons, then chop into dice. Trim the end off the salad onion. Finely slice it. Halve the olives. Pop the chopped veg in a bowl. Finely slice the mint leaves. Add to the salad.
Whisk the reserved garlic, lemon zest and juice with 1 tbsp olive oil and some seasoning to make a dressing. Drizzle over the salad and toss to coat. Crumble ½ the pack of feta over the top of the salad. Set aside.
Heat your grill to high (if you don’t have a separate grill from your oven, you can cook the skewers in a griddle or frying pan on the hob). Thread the beef strips onto the skewers. Grill for 8-10 mins, turning occasionally, till the beef is charred and cooked through. Serve the beef skewers with the chips and salad.