Grate the onion on the large holes of a box grater. Wrap it in a clean kitchen towel and squeeze hard for about 30 seconds, until no more liquid drips out. Wet onion is what makes the mixture slump.

Put the beef, squeezed onion, parsley, 3 grated garlic cloves, cumin, coriander, paprika, cinnamon, 2 tsp salt and pepper in a large bowl. Mix with your hands for about 1 minute, just until the spices are evenly spread. Divide into 12 portions of about 75 g and roll each into a log about 10 cm long and 3 cm thick. Set them on a parchment-lined 33 x 46 cm / 13 x 18 inch baking sheet and refrigerate for 30 minutes.

While the logs chill, stir the Greek yogurt, 1 grated garlic clove, 1 tbsp lemon juice, mint and 1/2 tsp salt together in a small bowl. Cover and refrigerate. Dice the cucumber and tomatoes into 1 cm pieces and keep them undressed in the fridge.

Heat a 30 cm / 12-inch cast-iron skillet over medium-high heat for 2 minutes. Add 1 1/2 tsp olive oil and lay in 6 logs with space between them. Cook for about 8 minutes, turning every 2 to 3 minutes, until deep brown on all sides and 160 F / 71 C in the center of the thickest log. Move them to a plate and tent with foil.

Add the remaining 1 1/2 tsp oil, let the pan come back to heat for 30 seconds, and cook the other 6 logs the same way, again until 160 F / 71 C in the center.

Right before serving, toss the cucumber and tomatoes with 1 tbsp olive oil, 1 tbsp lemon juice and 1/4 tsp salt. Plate 3 kofta per person with the salad and a few spoonfuls of yogurt sauce.