Okay, this one takes some time to make, but it is worth spending time - IF you have time :).
1) Boil 4 potatoes, then peal the skin (while they are still hot). Put them in a bowl and mash them with a folk (not too much but just enough). Put a wrap over the bowl and let it cool.
2) Sauté minced onions (half a onion is enough) and approx 100g of ground meat (chicken, turkey, pork, or beef) thoroughly (but don't burn them). Let it cool.
3) Once 1 and 2 are cooled down, mix them together with 3-4 table spoons of milk. Don't mash them too much.
4) Make balls or any forms you wish to make with the mix. I sometimes put cheese or quail eggs inside.
5) Make batter by mixing 1 egg, flour (5 table spoons), olive oil (1 table spoon), and some milk (until the batter gets smooth but with good consistency).
6) Dip your balls into the batter, and then to Panko (Japanese breadcrumbs). Let them sit for a while.
7) Heat up your oil to 170C, and fry the balls (croquette) until they are brown outside.