To cook couscous, in a small saucepan, bring 1.5 cups of water to a boil. Add couscous and salt and reduce the heat to simmer. Cover and continue to cook for about 10 minutes, stirring occasionally. When done, couscous is tender, but not mushy, and water is fully absorbed. Fluff cooked couscous with a fork and cool to room temperature.
To prep the vegetables, slice the cucumber into half moons, or quarters. Slice the tomatoes in half and cut the sweet peppers into thin strips.
To make the dressing, combine olive oil, lemon juice, chopped mint and za'atar in a small bowl, or 2-cup measuring cup.
To toss the salad, combine cooled couscous, cucumber, tomatoes, sweet peppers, feta cheese and dressing. Mix well and serve. This salad is best served at room temperature, in my opinion, but can also be served chilled. Store the salad in the fridge.
Note 1: Pearl couscous, aka Israeli couscous, is a small ball-shaped pasta the size of a black peppercorn. Don't confuse with Moroccan couscous, tiny little grain-like pasta, which require a little different cooking method.