Have ready a colander and an ice bath, and bring a medium pot of lightly salted water to a boil.
Blanche peas for 30 seconds (if you like them with a real residual snap) to 1 minute (for a slightly more yielding pea) and drain them, then immediately shocking them in the ice water.
Drain the peas again and pat them dry on a large towel.
Using a potato or egg-masher, muddler or meat pounder, lightly crush the peas. Aim for mixed textures, some left whole, most in halves and a few a little more broken up. Put them in a large bowl.
Whisk together tahini, yogurt, lemon juice, water, cumin, paprika and salt.
Mix peas with about 3 tablespoons of the dressing, to start, then add more to taste.
Sprinkle with scallions. Heap pea mixture on toasted pita wedges.
