Squeeze excess moisture from zucchini.
Place zucchini, onion, peas, mint and flour in a large bowl. Add egg. Season with salt and pepper. Stir to combine.
Add enough oil to a deep frying pan to come 5mm up side of pan. Heat over medium heat. Spoon 2 level tablespoons batter into pan, spreading slightly with a spatula. Repeat to make 4 rounds.
Cook for 2 to 3 minutes each side or until golden and cooked through. Transfer to a plate lined with paper towel. Repeat with remaining mixture. Serve.