I dont like goats cheese so wondered what else I could use in a Portobello mushroom?

I think that you can use any cheese you want. I have used cheddar and mozzarella. Watch out for the calories though cheddar has nearly twice as many as mozzarella, but I use a mature version so less still has some taste.

I usually top it with a scrambled egg – either one egg for breakfast or two for lunch. I add some feta cheese to that some days – it softens in the egg and adds both texture and flavour. Parmesan is also good grated on top of mushrooms especially if you put a little garlic underneath.
Cheese is calorie dense, so although dairy and not banned, it is recommended to be eaten in small amounts. Most cheeses are ok and as FoFi says, go for ones with a strong taste and I think there is a comment on using hard cheeses not brie, but I can’t find that just now.