You’ll need 16 skewers. If using wooden ones, soak in water for 30 mins first to prevent them from burning. Whisk the lime juice, harissa and honey in a large bowl. Add the beef strips and toss everything together. Leave to marinate for at least 1 hr (or up to 4 hrs if you have time).
To make the dip, whizz all the ingredients together in a food processor, then chill until needed.
Heat the barbecue or a griddle pan until smoking hot. Thread 2 pieces of beef onto each skewer, winding them around the skewer as you do, then season. Cook for 1 min on each side for medium- rare skewers, or longer if you prefer them well done. Serve warm with the dip.