Thinly slice the English cucumber into 1/8-inch rounds and set aside on a clean cutting board or plate. Halve the red onion lengthwise, then thinly slice into half-moons. I recommend slicing the cucumber and onion separately so you can add them to the salad at slightly different times—the onion benefits from a few extra minutes to soften and mellow its sharp bite before serving.
In a medium bowl, whisk together the cashew yogurt, Dijon mustard, apple cider vinegar, fresh lemon juice, grated garlic, and date syrup until smooth and well combined. The mustard and vinegar will add brightness and prevent the dressing from tasting one-dimensional, while the date syrup balances the acidity with subtle sweetness. Whisk until there are no lumps and the mixture is creamy and uniform.
Add the extra virgin olive oil, red pepper flakes, salt, and black pepper to the dressing from Step 2, whisking until fully incorporated. Taste and adjust seasoning as needed—you may want additional salt or a squeeze more lemon juice depending on your preference. The red pepper flakes add a subtle warmth without overwhelming heat.
In a large serving bowl, combine the sliced cucumber from Step 1, sliced red onion, drained and rinsed chickpeas, and chopped fresh dill. Pour the seasoned dressing from Step 3 over the vegetables and gently toss until everything is evenly coated. I like to let the salad sit for 10-15 minutes before serving so the flavors meld together and the vegetables soften slightly while absorbing the dressing.