In a medium-sized bowl, whisk together the flour and salt.
Chop the butter into small cubes and add it into the bowl. Use your fingers to work he butter into the flour until it disappears. This will take about five minutes.
Start with the smaller amount of hot water and pour it in. Quickly stir the mixture together with a fork or whisk to bring the dough together. It'll look a little messy but that's okay. Use additional water if needed to bring the dough together.
Put the dough onto a lightly floured surface and knead briefly, just until the dough forms a ball. If the dough is very sticky, add a little bit more flour. Allow the dough to rest, covered, for about 30 minutes. You can add a bit of olive oil to the dough to prevent it from sticking if you'd like. After the dough has rested, preheat an ungreased cast iron griddle or skillet over medium high heat.
Divide the dough into eight balls. Working with one dough ball at a time, roll into a round about 8 inches in diameter. Some of ours came out as rectangles - it's fine. Get them as thin as you possibly can.
Fry the tortilla in the ungreased pan for about 30 seconds on each side - just until small brown spots begin to form. Wrap the tortilla in a clean cloth when it comes off the skillet. Repeat with remaining dough balls.