Thaw the Tribeca Oven Classic Stiratos for 15 minutes and bake in a convection oven at 385℉ for 4-6 minutes. Let rest for 20 minutes before cutting in half lengthwise.
Preheat a convection oven to 400℉. Place the drained chickpeas on a parchment-lined sheet pan and add the vegetable oil and curry powder and toss until coated. Season with salt and ground black pepper to taste. Place in the oven for 8 – 10 minutes. Lightly mash the chickpeas while hot and set aside to cool before adding to the curry aioli.
Make the quick-pickled red onions by combining the apple cider vinegar, water, sugar, and salt in a small pot over medium-high heat. Once the mixture comes to a boil, turn off the heat and pour over the thinly sliced red onions in a heat-safe container. Let sit at room temperature for at least 20 minutes before using. Refrigerate any remaining pickled onions for later use.
Make the curry aioli by combining the vegan mayonnaise, curry powder, parsley, garlic, and lemon juice and zest. Stir to combine and add salt and ground black pepper to taste. Mix with the mashed roasted chickpeas to make the salad.
To build the sandwich, scoop about ½ cup of the curried chickpea salad onto the bottom portion of the bun. Top with the pickled red onions, ¼ of the thinly sliced avocado, and baby spinach.