What is the best type of olive oil, hard cheese, and bread, to make grilled cheese sandwiches?

Crusty white sourdough
Havarti cheese
Butter or lard instead of oil (but if you must do oil, use something you like, but extra virgin will tend smokier. The best oils tend to come from smaller producers and counterfeiting/adulturation is rampant.

Rye bread with seeds, Jarlsberg cheese shredded (piled high) and I use mayonnaise not oil or butter !

I second sourdough.

I’m simple – white bread, american cheese (2 slices cut to fit the entire slice of bread) and butter. Grill it, and keep peeking under the sammich to see how brown it’s getting; flip over, repeat. I’ve never heard of putting a grilled cheese in the microwave and can’t imagine it would be good. The cheese melts during the grilling.

I also use butter. I think my favorite cheese with the sourdough is smoked Gouda.

Well, I don’t use the microwave, for one. Also, I use margarine instead of olive oil. I’m not sure what you mean by hard cheese, but I don’t use the processed cheese slices because they have way too much sodium. I actually use shredded cheese (mild cheddar), and also put pepperoni on mine.

@smudges except for your choice of cheese (I sue shredded), I agree! Also, I make sure my pan is really hot, which helps grill the bread faster. I actually put the bread in the pan and then build my sandwiches up from the bottom while the bread is grilling.