Blini are a traditional Russian, Ukrainian, and Belorussian dish of thin yeast dough pancakes made from wheat or buckwheat flour. They are usually savory, and are typically served as finger food or canapés. Blini are smaller than American-style pancakes but not as paper-thin as crepes.

Adam says of his blini: "I'm using buckwheat flour, dried apple, eggs and ricotta."

He says "dried apple" Dehydration of apples takes at least 3 hours, so I'm guessing that Adam brought dried apples with him. We see a shot of him peeling a Granny Smith, so I'm guessing thats for the topping. 

Traditionally, blini are made with yeast and a proving process, but the implication from the Great British Menu is that not a lot of time is invested in the making of canapes, so Adam almost certainly swapped out the yeast and instead used baking powder and baking soda instead. There is a recipe here which is the closest I can get to the dish that Adam prepared.