Add the flour and salt. Mix with a stiff spatula or wooden spoon until floury, shaggy dough forms. Turn the dough out onto a work surface and knead until it forms a smooth, slightly tacky ball that springs back when you poke it, 5 to 8 minutes. If the dough sticks to your hands like bubblegum, add a tablespoon of flour at a time until it’s easier to work with; avoid adding too much flour if possible.