How to Make It
In a food processor, pulse the chickpeas until finely chopped. Add the tahini, lebneh, garlic, vinegar, salt and 2 tablespoons of water and puree until very smooth; add more water if needed for a smooth puree. Spread a scant 1/4 cup on each of 4 plates. Reserve the rest of the puree for a dip or another use.
In a small bowl, whisk the grapeseed oil with the sherry and balsamic vinegars and the shallot; season the vinaigrette with salt and pepper. In a medium bowl, mix the mayonnaise and Sriracha; add the shrimp and turn to coat.
In a large skillet, heat 1 tablespoon of the olive oil over moderately high heat. Add the romaine hearts cut side down and cook until browned, 1 to 2 minutes. Transfer to the plates, cut side up.
In the same skillet, heat 2 tablespoons of the olive oil. Add half of the shrimp and cook, turning once, until browned and just white throughout, 4 to 5 minutes. Transfer to 2 of the plates. Repeat with the remaining olive oil and shrimp.
Whisk the vinaigrette and spoon it over the romaine and shrimp. Garnish with the sesame seeds and lemon zest and serve.