1. Sauté shishito peppers in a skillet over medium heat until blistered.
2. In the same skillet, add garlic and shallots, sautéing until fragrant and tender.
3. In a blender, combine sautéed peppers, garlic, shallots, tahini, white wine vinegar, nutritional yeast, lime juice, salt, pepper, and cold water. Blend until smooth and creamy.
4. In a large bowl, mash chickpeas roughly with a fork, then mix in the creamy tahini dressing.
5. Adjust the sauce for desired thickness by adding more water or lime juice as needed.
6. Toast slices of whole-grain or sourdough bread.
7. Assemble the sandwich by layering lettuce, fresh herbs, and chickpea-tahini mixture between the toasted bread slices.
8. Add grilled halloumi cheese for extra protein if desired.
9. Serve immediately and enjoy this deliciously textured sandwich.