GRILLED PORTOBELLO STEAKS WITH GARLIC WHITE BEAN MASH AND A HERB GREMOLATA | Australian Mushrooms

Ingredients

• 4 Portobello mushrooms, thickly sliced
• 1 tbsp butter
• ½ cup parsley, finely chopped
• 1 tbsp marjoram, roughly chopped
• 1 lemon zested
• Juice of 1/2 lemon
• 1 garlic clove, minced
• ¼ cup olive oil, plus extra for serving
• Pinch sea salt
• ½ leek, thinly sliced
• 2 400g cans of butter beans, drained
• ½ tbsp marjoram, roughly chopped
• ¼ cup milk
• ¼ cup parmesan cheese, grated
• Pinch fresh cracked pepper