Add the water, whisked egg, and melted butter. Stir until you have a slightly sticky dough. If the dough feels dry, incorporate a little more water; if it’s too sticky, sprinkle in some extra flour.
Knead the dough for 3 to 5 minutes until smooth and elastic. Cover the bowl with a damp towel and let the dough rise in a warm spot for about 1 hour or until doubled in size.
Turn the dough onto a floured surface and roll it to 1/3 inch thick. Use a 2-inch round cookie cutter to cut slider shapes. Re-roll leftover dough for more pieces.