Rinse the barley. Set a lidded pan over high heat. Add the barley, juniper and a pinch of salt. Lower heat. Cover with 1cm water. Pop the a lid on. Simmer 25 mins or till all the water's absorbed. Let it steam, lid on, a further 5 mins once cooked.
Thinly slice your mushrooms. Set a large frying pan over high heat. Add the mushrooms and 1 tbsp oil. Season well. Cook till nicely coloured, adding more oil if needed.
Finely dice the apple and fennel. Finely chop the flat leaf parsley. Whisk the yogurt with half the parsley and a pinch of salt.
Add the lemon zest and juice to the barley. Remove the juniper berries. Fold the mushrooms, apple and fennel through. Season to taste. Dish up. Scatter the parsley over the top. Finish with a drizzle of olive oil. Serve with dollops of the lemon parsley yogurt.