Make the tzatziki first. Peel the cucumber and grate it. Place the grated cucumber in a sieve and squeeze out as much liquid as possible. Chop the garlic and dill finely. Put the cucumber, yogurt, garlic, dill and some salt and pepper in a bowl and stir to combine. Refrigerate the tzatziki for at least 2 hours before serving.
Chop the garlic, mint and parsley finely. Put all the ingredients for the keftedes in a bowl and knead together. If the mincemeat mixture is still a bit wet, add a third tbsp of the breadcrumbs.
Form small balls, about 4 cm. Fry the meatballs in a pan with a dash of oil or butter. Turn them on regularly and bake them for about 10 min.
Serve the keftedes with the homemade tzatziki.