Put the chicken fillet and onion, eggs, salt and pepper in a blender. Chop well.Cut the feta into small cubes, add the chopped dill and mix.Brush muffin molds with butter. Put the first layer of 1-2 tablespoons of chicken mixture. Then spread the feta and dill evenly. And put the last layer of the remaining chicken mixture.Bake in the oven at 180 ° for 20 minutes.