- Preheat the oil in a deep fryer to 350°F (180°C). Line a plate with paper towels (see note).
- Prick the potato all over with a fork. In a microwave, cook the potato for 4 minutes or until tender. Let rest for 5 minutes.
- Cut the potato in two and scoop out the flesh with a spoon. In a bowl, mash the potato flesh with a fork and combine with the mayonnaise and lemon juice. Add the crab and green onions. Season with salt and pepper. Using your hands, form the mixture into 4 thick patties.
- In a shallow dish, place the flour. In a second shallow dish, lightly beat the egg. In a third shallow dish, place the breadcrumbs.
- Dredge the patties in the flour, shaking off any excess. Dip into the beaten egg, letting the excess drip off. Then press into the breadcrumbs and coat well.
- Carefully drop 2 patties at a time into the hot oil. Watch out for splattering. Cook for 2 minutes or until nicely golden, turning the patties over as they cook. Drain on the paper towels.
- In a bowl, combine all of the ingredients. Season with salt and pepper. Serve with the crab cakes.
Instead of deep-frying the crab cakes, you can cook them in a non-stick pan with 2 tbsp (30 ml) of vegetable oil over medium heat for 8 minutes, gently turning them over halfway through. However, the breadcrumbs do not get as golden and crispy when cooked with this method.