Place thinly sliced red onion in a heatproof bowl or jar. Stir together apple cider vinegar, water, sugar and 1 tsp salt until sugar and salt dissolve. Pour the brine over the onions, press the onions down so they’re submerged, and let sit at room temperature for at least 15 minutes (or up to 2 hours). Drain before assembling salad; reserve a tablespoon of the pickling liquid to add to the dressing if desired.

Pita croutons

Bake or pan-fry pita

Preheat oven to 375°F (190°C). Toss pita pieces with 1 tbsp olive oil, 1/2 tsp sumac or smoked paprika (if using) and 1/4 tsp salt. Spread in a single layer on a baking sheet and bake 10–12 minutes until golden and crisp, tossing once halfway. Alternatively, heat a skillet over medium and toast in batches, stirring, until crisp, about 6–8 minutes. Set aside to cool.

Tahini vinaigrette

Make the dressing

In a bowl whisk together 4 tbsp tahini, 3 tbsp lemon juice, 2 tbsp olive oil, 1 tsp minced garlic, 1 tsp ground cumin, 1 tsp maple syrup or honey, 1 tsp salt and 1/2 tsp black pepper. The mixture will thicken; whisk in water, 1 tbsp at a time (about 3 tbsp total) until you reach a pourable, creamy consistency. Taste and adjust: add more lemon for brightness, salt for seasoning, or water to thin. If using, stir in 1 tablespoon of the reserved pickling liquid for a tangy note.

Salad assembly

Prep vegetables and cheese

Wash and spin dry the salad greens. Peel or scrub the cucumber, halve lengthwise and slice thinly (about 1/4-inch). Crumble the feta if not pre-crumbled.

In a large bowl toss the greens and sliced cucumber with about two-thirds of the tahini vinaigrette to lightly coat (you can reserve some dressing to serve on the side). Add the pickled red onion (drained) and gently toss to combine.

Scatter crumbled feta and pita croutons over the top. Drizzle with remaining dressing and a small drizzle (about 1 tsp) of extra tahini if using. Sprinkle chopped parsley over the salad and serve immediately so the croutons remain crisp.