Chicken With Japanese-Style Mushroom Sauce

INGREDIENTS

• 2 large chicken breasts
• 1/3 cup potato starch katakuriko (may be substituted with corn starch)
• 1 -1 1/2 cup shimeji mushroom
• 4 -5 shiitake mushrooms
• 6 white button mushrooms (brown mushrooms would also work)
• 1/2 yellow onion
• 2 garlic cloves
• 3/4 cup olive oil
• 2 tablespoons olive oil
• 1 tablespoon soy sauce
• 1 tablespoon mirin
• 1 pinch salt and pepper
• 1 tablespoon butter