I know that mushrooms can be frozen but they most be either flash frozen,
par boiled or sautéed first.

I got a box of white button mushrooms for $1.19 and they need to be used
soon. But I have no need to use them tonight as we have plenty of leftovers.

My plan is to use some in a chicken and rice pilaf and some in a tuna
casserole (white sauce with mushrooms added).

None of us are big into mushrooms. It's the texture we don't like, but we do
like the flavor. Normally, I will whack the fresh ones with the side of the
knife to smash them and then mince them finely. I usually only use 2-3
mushrooms (depending on size) when the recipe calls for 8 oz. That amount is
doable for us.

So which method would you use? And should I leave them whole? I will
probably use some next week or later this week.

Thanks!