Mini burgers have officially gone the way of the cupcake: delicious, but ubiquitous. Instead of the usual beef on a bun, here are five filling and inventive alternatives.

Poached Maine lobster with lemon and chives on a homemade bun, from Taste Caterers in New York
Photo: Peter LaMastro for BizBash

Ancho-chocolate duck confit with avocado salsa on a cornbread muffin, from 10tation in Toronto
Photo: Tracycoxphoto.com for BizBash

Torta Cubana with ham, refried beans, and avocado, from Blue Plate Catering in Chicago
Photo: Michael Maes for BizBash

Caprese sandwich with bresaola on a mini sesame-seed roll, from Food Fetish in Los Angeles
Photo: Carin Krasner for BizBash

Seared ahi tuna on a crispy nori bun with wasabi mustard, from Susan Gage in Washington
Photo: Renee Comet for BizBash