In a large bowl, whisk together the flour, sea salt, sugar, and baking powder until evenly mixed.

Add cold, cubed or grated butter. Use a fork or pastry cutter to work it into the flour until the mixture resembles coarse crumbs with pea-sized pieces.

Crack in the egg, then add the sourdough discard and milk. Stir with a spoon until the dough comes together into a shaggy ball. Do not overmix.

Turn the dough out onto a lightly floured surface. Fold it a few times to incorporate any loose flour — don’t knead.

Roll the dough into a square about 1/4" thick. Use a pizza cutter or bench scraper to cut into roughly 1/2" x 1/2" squares.

Drop dumplings into a large pot of boiling soup set to medium–medium-high heat.

Cook for about 15 minutes. Test a dumpling with a fork to confirm doneness. If they’re still dense in the center, lower the heat to low and cook 5 more minutes before checking again.