Remove the stems from the mushrooms and slice them into thin strips. Set the caps aside.
Heat a frying pan over medium heat with a good knob of butter and a drizzle of oil. Add two minced garlic cloves and the sliced mushroom stems.
Fry until fragrant, then add the mushroom caps. Cook for 5-7 minutes, turning occasionally, until they soften and release their juices.
Meanwhile, grate a mix of mozzarella and cheddar.
Once the mushrooms are soft, push them to one side of the pan and sprinkle the cheese mix directly onto the pan.
Place the mushroom caps on top of the melting cheese, letting it crisp up beneath them. Cook for 3-5 minutes until golden and crispy.
Carefully flip the mushrooms so the crispy cheese layer is on top, then cook for another minute.
In the same pan, add a little more oil and fry a few sage leaves until crispy—about 1-2 minutes.
Plate up the stuffed mushrooms, top with crispy sage, and drizzle over balsamic glaze. For a little extra zing, scatter over some pickled onions.
BIFF, BOSH, NOSH!
