Fluffy Whipped-Egg-White Banana Pancakes

Steps

1. Dice the banana, chop the walnuts and separate the eggs into whites and yolks before you start. Melt half of the butter and let it cool slightly.
2. In a large bowl, whisk the flour, sugar, baking powder, baking soda, salt and nutmeg.
3. In a second bowl, whisk the egg yolks, kefir, the melted butter and the vanilla until smooth.
4. In a clean bowl, beat the egg whites with a whisk or mixer until they hold soft peaks.
5. Pour the kefir mixture into the flour mixture and stir just until no dry flour remains; a few lumps are fine.
6. Gently fold the beaten egg whites into the batter in two additions, then fold in the banana and walnuts. Let the batter rest 5 minutes.
7. Heat a large nonstick skillet over medium-low heat and brush it with a little of the remaining butter, using about a quarter of it for each batch.
8. Pour about 1/3 cup of batter per pancake and cook 2 to 3 minutes until bubbles form and the edges look set, then flip and cook 1 to 2 minutes more until golden and cooked through in the center.
9. Keep finished pancakes warm on a plate under a towel while you cook the rest of the batter, buttering the skillet with the rest of the remaining butter between batches. Serve warm.