For the cakes:
Add the potato to a steamer and steam until fork tender (I like to steam for these cakes, as it reduces water content and makes them hold together better), remove from saucepan, mash and set aside.
Drizzle a frying pan with some olive oil and add the onion and grated carrot, fry for a few minutes to soften. Sprinkle with the mixed herbs and a little black pepper.
Add mixture into mashed potato and mix all ingredients together well. Form into equal size cakes. You can make them which ever size you wish. I made 15 mini sized cakes.
Refrigerate for an hour or so to firm up.
These can then either be shallowed fryed with a little bit of oil, or can be placed on some parchment on a baking tray and baked at 200c or 400f (gas mark 6) until golden on each side. Approx 20-30mins.
For the sauce:
Drizzle a frying pan with a little bit of olive oil, add the onion, garlic and carrot and fry for a few minutes to soften.
Add the passata and stock, bring to a boil and simmer, covered for approx 20 mins until sauce reduces down. Add to a blender and blend till smooth.
This can be served warm or cold. Refrigerate or freeze any extra sauce for another day.