Preheat the oven to 375°F (190°C).

In a large bowl, combine self-rising flour with cold butter. Use a pastry blender to create coarse crumbs. Add poppy seeds, sugar, and lemon zest, and mix to combine.

Make a well in the center of the flour mixture. Add beaten egg, fresh lemon juice, and milk. Mix with a fork until dough begins to form.

Transfer dough to a work surface. Use hands and a bench scraper to form a 1-1.5 inch tall rectangle. Cut into 4 squares, then diagonally into 8 triangles. Place scones on a silicone-lined baking sheet.

Bake for 25 minutes until bottoms are golden brown. Let them cool for 5 minutes in the pan, then transfer to a wire rack and let cool completely for 30 minutes.