Wash and then squeeze out any excess moisture from the mince. Set aside. Peel and chop the onions roughly, then grind them to a rough texture. Remove and squeeze out any excess moisture from the onions, then put them back in the grinder, add the chopped coriander, chillies, lemon juice, ginger and garlic pastes. Grind again to combine.
Put the beef/lamb mince into the processor with the onion paste mixture, and grind together. Turn this mixture out into a bowl, add the salt, black pepper powder, cumin powder, beaten egg, butter and 2 tbsp. of the breadcrumbs. Mix thoroughly, kneading the mixture well to ensure everything is properly combined. I normally knead the mixture for about 5 minutes and find this helps tenderise the mince and results in perfectly smooth seekh kababs. If the mixture feels a bit sticky, add 1 more tbsp. of the breadcrumbs.
Cover the bowl and refrigerate for about 30 minutes. When ready to shape the kababs, grease a baking tray lightly with oil.. If you want to make this authentic seekhi shape and do not have flat skewers, lightly oil the stick end of a wooden spoon, grab a small handful of the mince mixture and shape it over the stick, making sure to smoothen it so that no cracks form. Then gently slide the kabab off the stick onto the tray. Keep going until all are shaped.
Preheat over to 220C. It needs to be a HOT oven when you place the tray in. Bake/grill for about 10 minutes, then turn them over and give them another 5 minutes. At this point the kababs will still be slightly light in colour, but that is ok. We shall finish them off on a pan to give them a great colour just before serving, so don’t worry. Overcooking them in the oven will result in them hardening and we want them to retain their moisture. Remove them from the baking tray and if you want, you could smoke the kababs using a lit coal with a drop of oil to give them a good bbq aroma. You can also pack and freeze the kababs at this point.
Then just before serving the kababs, warm a frying pan and add a small drizzle of oil. Add the kababs on it in batches and keep turning them using tongs to get an even colour on every side. Remove them on to a plate and serve them juicy and sizzling hot with accompaniments of your choice.