Mix the milk and vinegar and set aside for ca 10 minutes so it thickens. Grate the apples and set aside as well. In a Mixing Bowl, combine the butter and sugar and mix well. Add the Chia seeds, vanilla, flour, buttermilk, water, baking powder and salt and mix until well combined. Add the grated apples and just spoon them under. Heat your waffle iron and bake delicious apple waffles.