Grate the courgette on the large holes of a box grater into a colander. Toss with 1 tsp salt and let it sit for 10 minutes so it releases water.
Squeeze the grated courgette by handfuls, or press it in a clean kitchen towel, until no more liquid comes out. This step decides if your fritters hold together.
Coarsely grate the halloumi using the same large holes.
In a mixing bowl, combine the squeezed courgette, grated halloumi, eggs, flour, spring onions, mint, garlic, and black pepper. Mix until it forms a thick, sticky batter.
Heat 1 tbsp olive oil in a 30 cm / 12-inch nonstick skillet over medium heat.
Scoop a scant 1/4 cup (about 60 g) of batter per fritter into the skillet, flattening slightly with the back of a spoon. Cook 4 at a time so they have room to brown, don't crowd the pan.
Fry for 3 to 4 minutes per side, until golden brown and set in the middle. Transfer to a paper towel-lined plate.
Add another 1 tbsp oil to the pan and repeat with the remaining batter, in 3 batches total, for about 12 fritters.
Serve warm, with lemon wedges or a yogurt sauce on the side.