Dice the pumpkin and potatoes bite-size and cook for a few minutes until partially cooked.
Dilute the sour cream with enough milk to make a smooth mixture. Season with the parsley, chopped garlic, salt, pepper and nutmeg.
You should use a little more salt so that it neutralizes the sweet pumpkin flesh.
Drain the potatoes and squash and place in an ovenproof dish (such as a casserole dish). Top with the sour cream mixture. Spread the cheese over the casserole and bake for 20-25 minutes at 200°C. Tip: As a pumpkin I recommend Hokkaido, because you can eat the skin with and do not have to peel first. Of course, you can also take cream instead of milk, but then of course the whole thing has more calories.