Cauliflower curry

Cauliflower (bloemkool) curry. Super taste vegetarian dish.
Ingredients:
4 el arachide oil
1 big cauliflower, in roses
1 onion, in half rings
2 toes of garlic, pressed
1 tl djahe (ginger powder)
2 potatoes, cut in small blocks
1 tl ketoembar (koriander powder)
1 tl cumin seeds (Albert Heijn)
1/2 tl cayenne pepper
1 tl koenjit (kurkuma)
1 tl garam massala (see below how to make the mix)
1 can santen (coconut milk)
salt
pepper
1 green lemon (limoen), 1/2 part: juice, 1/2 part, cut in slices
fresh koriander, cut in small pieces
fresh mint, cut in small pieces
1 pack of basmati rice

Preparation
Important: read very well, everything is a little bit time-critical
Heat 2 el oil in a pan and bake the cauliflower 5 min. Add potato blocks and bake 10 min on middle high fire. Roast the cumin seeds in a dry pan for 1 min.
In the meantime, heat another pan with 2 el oil, add the onion, garlic and djahe. Bake softly for 10min. Add cumin seeds, ketoembar, cayenne pepper, koenjit and garam massala. Bake 2 min.
Add cauliflower, potato blocks, lemon juice and santen. Bring to taste with salt and pepper. Close the pan and let it cook on low fire for 10min. When almost finished: add the fresh koriander and mint, and garnisch with the slices of lemon.
Serve with basmati rice, cooked with 1/2 tl koenjit and 1/2 tl garam massala.

Garam Massala mix: enough for about 5x cooking, depends on the dish
2 el djintan (kumin powder)
4 el ketoembar (koriander powder)
2 el kardemom powder
1 el black pepper
1 el cinnamon (kaneel)
1 tl tjenkeh (kruidnagel)
2 tl nutmeg (nootmuskaat)