Using a vegetable peeler or mandoline, slice each English cucumber lengthwise into long, thin ribbons. Stop when you hit seeds to keep ribbons crisp.

Cut the small onion into very thin half-moons and separate into rings. Soak in cold water for 5 minutes if raw onion feels too sharp, then drain.

In a medium bowl, whisk together whipped cream cheese, mayonnaise, soy sauce, rice vinegar, and sesame oil until silky and smooth.

Taste and adjust—add a little more soy if you want more saltiness or a splash more rice vinegar if you want brightness.

Flake in your choice of imitation crab, smoked salmon, canned tuna, or chopped cooked shrimp and gently fold to coat.

Toss the cucumber ribbons and onions with the creamy mixture, working gently so the cucumbers remain crisp.

Sprinkle furikake or everything bagel seasoning over the top and drizzle spicy mayo or a dot of sriracha if you like heat.