Grate the tomatoes on the large holes of a box grater into a bowl, skipping the skins. Stir in the 1/4 tsp salt and let sit for 15 minutes so the tomatoes release their juice.

Tip the tomatoes into a fine-mesh sieve and press with a spoon to squeeze out as much liquid as possible. You should end up with about 1 cup / 240 ml of thick pulp.

Grate the onion, then squeeze it in a paper towel to remove excess liquid. Add it to the drained tomatoes.

Stir in the feta, mint, oregano, and black pepper until combined.

Add the flour and baking powder a little at a time, stirring after each addition, until the batter is thick enough to hold its shape on a spoon. Add an extra tablespoon of flour if the batter still looks loose.

Let the batter rest for 10 minutes at room temperature before frying.

Heat the olive oil in a 25 cm / 10-inch skillet over medium heat until it reaches 175 C / 350 F, or shimmers when you drop in a bit of batter.

Drop heaping tablespoons of batter into the oil, 5 to 6 at a time so the pan isn't crowded. Fry for 3 to 4 minutes per side, until deep golden and crisp at the edges.

Lift the fritters out with a slotted spoon and drain on a plate lined with paper towels. Repeat with the remaining batter, lowering the heat slightly if the oil starts smoking.

Serve warm with lemon wedges or a side of tzatziki.