Tear the stale bread into rough pieces and place them in a bowl of cold water. Let them soak for 10 minutes until fully saturated. Then gather the bread in both hands and squeeze firmly until you cannot extract another drop of moisture.

Use the fine side of a box grater over a bowl to grate the red onion. You want juice and pulp, not pieces. A finely grated onion disperses throughout the mixture and flavors every bite evenly.

In a large mixing bowl, add the ground pork, ground beef, squeezed bread, grated onion, garlic, mint, oregano, parsley, ouzo, egg, salt, pepper, and paprika. Using clean hands, mix gently until just combined -- three to four passes is enough. Do not overwork.

Cover the bowl with plastic wrap and refrigerate for a minimum of 30 minutes, ideally one full hour. This step is not optional. The cold rest allows the meat to firm, the bread to finish absorbing moisture, and the flavors to integrate.

Set out a plate with the flour. Wet your hands lightly with cold water. Take a portion of the meat mixture (approximately 35-40g each). Roll briefly into an oval shape, then press gently to flatten slightly. Dredge each shaped keftedas lightly in flour and tap off the excess.

Pour the olive oil into a large, heavy frying pan to a depth of about 1cm. Heat over medium-high heat until the oil shimmers. Target temperature: 175-180C (350F).

Lay the keftedes into the oil in a single layer with clear space between each one -- never crowd the pan. Fry for 3-4 minutes on the first side without moving them. Flip once and fry for another 3-4 minutes until deeply golden-brown.

Transfer the finished keftedes to a plate lined with kitchen paper. Serve immediately with tzatziki and lemon wedges, or keep warm in a low oven (120C/250F) while you fry the remaining batches.