Roughly chop half the onion, setting the other aside for the sauce. Bash both garlic cloves and add one to a food processor along with the chopped onion, chicken, dried herbs and mushrooms. Pulse until well combined.
Preheat the oven to 180°C/gas mark 4. Tip the chicken mixture into a bowl along with the egg and mix well. Using slightly damp hands, shape into 12 meatballs, then put in the fridge to chill.
Bring a large pan of water to the boil and add the cauliflower. Boil for 10-12 minutes until tender, then drain well and mash with seasoning. Stir through the spinach and set aside to keep warm.
Lightly spritz a non-stick frying pan with the olive oil and brown the meatballs all over for 2-3 minutes (you may have to do this in batches). Place the browned meatballs on to a lined baking tray and bake in the oven for 12-15 minutes until cooked through.
Meanwhile, make the sauce. Finely slice the other half of the onion and cook for 3-4 minutes until just tender in the same pan used for the meatballs. Finely chop the remaining garlic clove and add to the pan, cooking for another minute.
Sprinkle over the smoked paprika and stir until well combined. Pour in the stock and bring to the boil, then simmer. Stir in the sour cream.
Serve the meatballs on a bed of mash, then spoon on the sauce and sprinkle with parsley and almonds.