In a large pot of boiling salted water, cook the pasta squares until al dente, about 5 minutes. Drain the pasta and cool under cold running water. Pat dry.
In a small bowl, mix the mayonnnaise with the 1/4 cup of chives and the lemon juice and season with pepper. In a medium bowl, toss the crabmeat with the peas. Fold in 1/3 cup of the chive mayonnaise.
Place 1 pasta square on each of 6 plates. Spread a small spoonful of the chive mayonnaise on each square and top with a scant 1/4 cup of the crab salad, spreading it to the edge of the square. Repeat the layering with another pasta square, another spoonful of mayonnaise and another scant 1/4 cup of the crab salad. Top with the final pasta square and a small dollop of chive mayonnaise. Garnish with a pinch of grated lemon zest, a pinch of chives and a sprinkle of pepper and serve.
Refrigerate any leftover chive mayonnaise for later use.