Wash and cut the courgettes in half and then each half in two lengthwise, from the center.
With a melon baller or a spoon carefully remove the zucchini pulp (the white part) making sure to leave at least around ½ cm of it around the shells.
Roughly chop the pulp and sauté until soft in a pan with the garlic and a pinch of salt.
Allow to cool down a bit, then blend until smooth.
Meanwhile add the burger patties in a large mixing bowl and crumble them with a fork.
Add the blended zucchini pulp and the potato flakes to the burger mix and stir up until everything is well combined. Leave the mixture for 10 minutes to firm up (depending on the water content of your zucchini, you might need to add more potato flakes to the mixture).
Preheat the oven at 180°C (355°F).
Place the zucchini shells/boats onto a baking tray, season with a pinch of salt, then fill with around ¼ of the burger mixture.
Sprinkle the corn flakes or the breadcrumbs on top of the filling and (optionally) finish with some vegan grated cheese and a drizzle of olive oil.
Bake for 25 to 30 minutes or until the zucchini shells are soft. You can finish on grill mode in the last 5 minutes for an even crunchier top.
Serve straight away or at room temperature.