Poach shrimp in simmering salted water with lemon quarters until firm and opaque, about 1–3 minutes depending on size. Cool in an ice bath, drain, and pat dry.
Fold shrimp and imitation crab together with celery, onion, seasoning, lemon juice, mayonnaise, and dill. Season to taste.
Cover and chill until serving; use within two days.
Contains shellfish and fish. Imitation crab often contains wheat and egg; read its label before treating this recipe as gluten-free.Inspired by Sara Welch.Estimated nutrition is for one of 4 equal portions. The estimate uses prepared imitation crab and the full mayonnaise dressing. The lemon used to poach the shrimp is discarded.Storage: Refrigerate perishable portions in shallow, covered containers within 2 hours, or within 1 hour above 90°F. Keep the refrigerator at 40°F or below and use cooked leftovers within 3–4 days. Keep any crisp toppings separate until serving.