This 7-layer couscous salad is an elevated version of one of my favorite go-to lunches. Instead of tossing together the ingredients in a bowl, I layer them in a trifle dish to instantly turn my everyday salad into an elegant centerpiece.
Combine the butter with 1/2 teaspoon salt and 1 cup water in a small saucepan and bring to a boil over medium-high heat. Stir to incorporate the melted butter, then stir in the couscous, cover with a tight-fitting lid and remove from the heat. Let stand until the couscous absorbs the water completely and is tender, 5 minutes. Fluff the couscous with a fork, transfer to a large bowl and let cool.
Whisk together the oil, lemon juice, 3/4 teaspoon salt and several grinds of pepper in a medium bowl until emulsified. Transfer the vinaigrette to an airtight container and set aside.
Combine the cucumbers with 2 tablespoons of the vinaigrette and 1/2 teaspoon salt in the same medium bowl and toss together.
Use a rubber spatula or small offset spatula to spread the hummus on the bottom of a 4-quart round trifle dish. Arrange the cucumbers on top in an even flat layer.
Transfer the couscous to the same medium bowl and stir in the onions, parsley and 3 tablespoons of the vinaigrette. Scatter the mixture over the cucumbers and gently press to flatten into an even layer.
Wipe out the medium bowl and add the tomatoes, 2 tablespoons of the vinaigrette and 1/4 teaspoon salt. Toss to combine. Arrange the tomatoes on top of the couscous, then top with the olives.
Toss the lettuce with 2 tablespoons of the vinaigrette and 1/4 teaspoon salt in the same medium bowl. Arrange the lettuce on top of the olives, then top with the feta. Drizzle the remaining vinaigrette on top and serve immediately.
If there is garlic on top of the hummus, stir to combine before measuring.
The lemon vinaigrette recipe makes about 3/4 cup and can be refrigerated in an airtight container for up to 2 weeks.