Last week while in Texas, we ate at Smash Burger, and I ordered the Cucumber Feta Chicken Sandwich (although its not listed on their menu on the website.) It was FANTASTIC. So fantastic that Laurel and I attempted to recreate it a couple days later at home.
It didn't turn out perfectly (the secret is to really smash the chicken thin) but it was still incredibly delicious. I think the cucumbers are the secret, they had such a flavor and crunch to the sandwich.
-Cook the chicken We cooked it on the stove/griddle thing. However, the key is to really pound/smash (hence smash burger) the chicken as thin as you can both before you cook it, and while it cooks. Just keep smashing and smashing.
-Place the chicken on the toasted bun.
-Next put the feta cheese on the chicken. This will begin to melt the cheese, which is so yummy and creamy, no other sauce is needed.
-Put on the cucumber, red onion, tomato, and if so desire the avocado.
-Lastly is the spinach and then the bun on top.
Sorry for no picture. I never took one.