Place the butter,celery,shallots and garlic in a medium-sized saucepan and cook over a low heat.
Add the freekeh and bay leaf to the pan and stir so the grain is coated in the butter. Add 230 millilitres of water to the pan,bring to the boil,then cover with a lid,reduce to a simmer and cook on a low heat.
Check the freekeh after 12 minutes and taste a small amount - the larger the grain,the longer the cooking time. When cooked (it should be al dente,with a slight bite),remove the freekeh from the pan and spread out on a large plate to cool quickly. When cold,it can be kept in an airtight container for two days.
Place the barberries in a small bowl,pour half a cup of boiling water over them and let them cool. When cool,pour off most of the water,leaving about one tablespoon,add the olive oil and vinegar and mix well.
Put the freekeh in a large bowl,removing the bay leaf,then add the tomato,cucumber and herbs. Pour the barberry dressing over and mix well. Add salt and pepper to taste.