Put the warm water in a large bowl, sprinkle with the yeast and let sit until it dissolves. (If you’re worried it might be inactive, let it sit for 10 minutes, until it gets foamy. If it doesn’t, you may need fresh yeast.)
Add the flour, oil (feel free to eyeball this—you don’t need to be precise) and salt and stir (or use the dough hook on your stand mixer) until the dough comes together, then knead for a few minutes, until smooth and elastic. (It will be very tacky—if it’s far too sticky to work with, add a bit more flour, but it will smooth out as it sits.)
Shape the dough into a ball if you like, return it to the bowl, drizzle with oil and turn to coat it all over. Cover with a tea towel or plate and let sit on the counter for at least an hour and up to several hours, punching it down now and then.
When you’re ready to bake, generously oil a 9x13-inch pan. Flatten the dough into the bottom, then flip it over so that it’s coated with oil and press until it covers the entire bottom of the pan. Press your fingers deep into the dough, straight through to the bottom, to create deep dimples. Cover and let it sit for another hour, preheating your oven to 425F toward the end.
If you like, drizzle the dough with a bit more oil, and sprinkle with flaky salt. Bake for 20-25 minutes, until deep golden. Turn out onto a cutting board to slice. Serves about 12.