Lemon soy butter mushrooms (like I ate in the Japanese mountains)

Lemon Soy Butter mushrooms, Japanese Mountain Style

Now, I say "Japanese Mountain" because once I went for a hike in the mountains in Japan and stopped in a lovely wooden tavern for food. The mushrooms were fresh Shitake, so the taste was different, but I liked how they were cooked so much that I do it often with portobello mushrooms (or portabello??? The producer's website uses both spellings, maybe they are two types but I cannot tell the diffence), to give them more taste.

1 x 250 g pack breakfast portabello mushrooms

1 tbsp rice bran oil

2 tbsp Japanese Soy Sauce (not Chinese, only use the Japanese one)

Juice of half a lemon

Lemon slices to decorate

20 g butter, cubed

Clean the mushrooms removing the outer skin as much as possible, and brushing them with a paper towel. Heat a skillet or a frying pan with 1 tbsp of rice bran oil and then add the mushrooms, cap facing down, stalks up. Make sure that you move the mushrooms around with a spatula so that they don't stick to the bottom of the pan, and that they brown lightly on the top of their caps before adding the soy sauce and lemon juice. Keep stirring and when all the liquid has been absorbed turn over, cover and simmer on low for about 10-15 minutes. You may need to add a little water (cultivated mushrooms tend to be much dried that foraged mushrooms) from time to time, and stir often to make sure that they are not sticking to the pan. Serve piping hot with a more lemon slices on the side and topped with the cubed butter (which will melt and taste delicious with soy sauce and lemon; did you know that?). 
Vegans can substitute butter for vegetable margarine.

Photos and Recipes by Alessandra Zecchini ©