Wash the potatoes and cook in a pan of boiling salted water for 20 minutes. Wash the broccoli and divide into florets.
Peel and finely chop the garlic.
Heat 2 tbsp oil in a saucepan and fry the garlic for 1 minute. Add the broccoli florets and cook for 4-5 minutes.
Pour in the stock and milk and simmer over a medium heat for 8-10 minutes. Add the cream cheese, remove the pan from the heat and blitz everything finely with a hand blender. Allow to cool.
Drain the potatoes, rinse under cold water, then peel and cut into slices.
Brush a casserole dish with the remaining oil and add the potato slices in layers.
Grate the parmesan and mix with the egg and broccoli puree. Season with salt, pepper and some freshly grated nutmeg. Pour the sauce over the potatoes.
Grate the gouda cheese and mix with the amaranth pops. Spread over the potato casserole.
Bake in a preheated oven at 200°C (180°C fan, gas 6) for 20 minutes. Meanwhile, wash the chives, shake dry and finely chop. Garnish the potato casserole with the chives.