Rinse the corn briefly in a sieve and drain well. Wash parsley, shake dry, pluck off leaves and chop finely. Crumble the feta finely. Mix sour cream, corn, parsley and feta, season to taste with a little salt and pepper.
For the skewers, wash the cucumber and cut it into slices about 1 cm thick in about 32. Cut half of the slices into triangles for the arrowheads, the remaining slices into arrowhead feathers. Roughly grate or chop the remaining cucumber slices for the tzatziki. Peel garlic and chop very finely. Mix yoghurt, cucumber and garlic. Season with salt and pepper.
Line a baking tray with baking paper. Preheat oven (electric cooker: 200 °C/circulating air: 175 °C/gas: see manufacturer). Peel sweet potatoes, cut in half lengthwise. Cut halves crosswise into 24 approx. 2 cm thick pieces. Cut bacon slices in half crosswise. Wrap 1⁄2 slices of bacon around the potato pieces and place on the tray. Bake in a hot oven for about 35 minutes.
For the meatballs, peel and finely grate the onion. Knead with minced meat, egg, crumbs, milk, mustard, ketchup, 1 slightly heaped teaspoon of salt and 1 level teaspoon of pepper. Form 60-64 small balls from the mixture. Heat the oil bit by bit in a large pan. Fry the meatballs in it in portions all around for about 6 minutes. First put the "cucumber feathers", then 4 meatballs and finally the cucumber triangles on skewers. If necessary, skewer the sweet potatoes with small twigs. Serve everything, tortilla chips taste good with it.