Gratin with ham and curry

This dish had been on my list for weeks but I never got around to actually cooking it. Now it's done and it was actually quite nice. I'm a huge fan of creamy sauces which makes this 'non dairy' diet extra hard but I know that it's probably better for me to cook with it as little as possible. I didn't have any carbs with this meal but I think it would be really good to have some rice with it in order to soak up sauce.

Ingredients
1 brown onion
1 red onion
1 leek
2 cloves of garlic
2 tbsp curry powder
600 grams of shredded ham
5 mushrooms
1 red capsicum
1 yellow capsicum
1 green capsicum
2,5 dl cream
2 dl creme fraiche
chili powder
salt and pepper
grated cheese (as much as you want)

Put the oven on 225 degrees.
Chop the onions finely and fry them in a frying pan together with some butter and the curry powder. Put them in a oven proof dish. Add the ham to the frying pan and let it soak up the curry flavours. Put the ham on top of the onions in the dish. Cut the mushrooms and capsicums in slices and fry them in the frying pan as well for about 5-10 minutes. Add these vegetables to the oven proof dish.
Mix together the cream, creme fraiche, chili powder, salt and pepper. Be careful with the salt since the ham is probably already quite salty. Pour this on top of the rest of the ingredients.
Cook in the oven for about 15 minutes. Take it out and add the grated cheese and cook for another 15 minutes.