Why when cooking mushrooms, you can add like, 3 tablespoons of oil and it just dissappears immediately and you need to add more, but you add a tablespoon of butter and it coats all of them mushrooms,,, where does the oil go? The mushrooms dont feel oily, what is going on here?

The mushrooms absorbed it. It’s jn the mushrooms. They’re mostly water and air in there, the fungus is almost nothing but a big sponge.

Mushrooms are mainly chitin - similar to shells of seafood! They have a porous structure and will absorb the oil. I feel they get kind of slimy when cooked in oil or butter.

There are two cool techniques that you can use when cooking mushrooms to make use of their composition and get what I find is a better texture.

The first is from Adam Liaw, who has an Australian cooking show. He puts the mushrooms in a bowl in the microwave and nukes them until they are soft. You don't need to worry about the exact time because the chitin is unaffected except the pores collapse. You end up with a bowl of mushrooms in mushroom broth and then they maintain a nice texture when cooked further in oil. This is a great technique if you can use the broth in your dish.

I can't remember where the second comes from. Maybe Modernest Cuisine. It is to dry fry the mushrooms. No oil, just mushrooms in the pan. Any liquid is evaporated as it is released. You can hear it squeak as they fry. The surface of the mushrooms gets nicely browned and then the mushrooms don't absorb the oil in later stages of cooking.

To properly brown mushrooms you should heat them on a dry pan and then finish with your desired oil/butter at the very end. Otherwise they can absorb a ridiculous amount of it like a sponge.

mushrooms usually only get slimy when cooked in oil or butter if they aren't cooked well done. If you cook them long enough to reduce the extra oil comes back out as they shrink.

they release water first, then soak up whatever remains

A third way is to put the mushrooms in a pan with water, cook until water is almost gone and then add oil and cook until browned. I’ve also added oil with the water and it turns out fine without having to watch as closely.

This! Get some colour on them bad boys!

To properly brown mushrooms you should heat them on a dry pan and then finish with your desired oil/butter at the very end. Otherwise they can absorb a ridiculous amount of it like a sponge.

I always cook them with a bit of water first and then add oil / butter. Otherwise yes, the mushrooms will absorb the oil and they could be a bit greasy.

In the sink

The microwaving idea I’ve never heard of! Definitely going to try it next time!

America’s Test Kitchen recently put out a YT video. There were 3 or 4 different chapters. I think mushrooms were last. You'll have to do a little searching.