Preheat oven to 200℃ (400℉)
Boil potatoes in water until soft to mash
Meanwhile, in a nonstick frypan dry-fry the onion with the garlic allowing the onion to caramelise, see notes below.
When the potatoes are soft, drain, then add all the other ingredients, including the onion mix.
Line a baking tray with parchment paper. On the baking sheet use the ring mould, scoop in the potato mix pressing down firmly, adding the mix until the ring is full. Top the potatoes with a sprinkle of nutritional yeast.
Using the pusher, remove the ring and repeat the process until all of the mash potato mix is used.
Bake in the oven for 10 minutes, then remove and gently baste the top of each cake with some plant milk. Return to the oven and continue cooking until the cakes are golden brown.