Prepare the couscous: Put the couscous into a large bowl. Pour over the boiling water or stock and stir. Cover with a plate or cling film and leave to stand for 5 mins until all the liquid has been absorbed. Separate the grains by roughing them up with a fork.
Finely dice the vine-ripened tomatoes and the cucumber. Slice the spring onions and finely chop the parsley, then add everything to the couscous with the grated zest of a lemon.
Whisk the olive oil, lemon juice and the garlic with plenty of seasoning and drizzle over the couscous. Toss well and serve with some grilled fish, meat or chicken.