• Start with the Dip: In a food processor (I use my mini for this), Combine cheeses and olive oil until silky smooth. Scoop into bowl, cover & refrigerate. Done.

Onto the Filling

• For the mushrooms- I put them into the food processor and pulse about 10 - 12 times until they are uniformly chopped with no pieces bigger than a pea. Ideally, a lentil size... but you don't want them to be complete mush.
• Heat a large saute pan over medium high heat and drizzle in the tablespoon of olive oil. Saute mushrooms until they have released ALL of their liquid. Stir occasionally so they don't burn, when they are almost dry, you can turn down the heat to let the last of the liquid evaporate.
• (This step is VERY important, so don't get impatient. If you put wet mushrooms into the phyllo, it will be a soggy mess)
• Once the mushrooms have given up all their liquid, combine them with the olives, feta & oregano.
• Stir to combine and set aside.

Assembly

• Unwrap phyllo dough and unroll so it's flat. Lay clean kitchen towel over it. You must keep it covered or it will dry out.
• Place 1 sheet of phyllo on the counter with the long edge closest to you (it's paper thin and very fragile... be patient) using the pastry brush, brush a thin layer of butter over the phyllo and place another sheet of dough on top. Repeat once more. You should have 3 layers of phyllo now with butter between each layer.
• (If the phyllo rips, it's not a big deal... Place another sheet on top and butter it up. Once it's assembled, you'll never see it.)
• Place a layer of the filling on the edge closest to you. I find it easiest to do this with a piping bag, but if you don't have one, a spoon works fine. You'll want the filling to be about as thick as a stalk of celery.
• Once you have a line of filling across the length of phyllo, roll it up tightly and butter the top.
• Try to work as quickly as you can, as the phyllo tends to dry out and you don't want it to break. If you notice that it is starting to dry out: put some butter on it. It will buy you some time
• Once it's all rolled up and buttered, cut into 2 inch pieces and place on a sheet pan.
• Cover and refrigerate. Repeat until filling is gone.

Bake

• Place in a 425 - 450 degree oven for about 10 minutes, or until golden brown. Keep a close eye on them. (They will go from pale to burnt quickly.)