Combine the atta and salt in the bowl of a stand mixer fitted with a dough attachment.
Turn the mixer on to medium speed to start mixing. Slowly add in 1 cup of water, letting it mix with the dough before adding more. If the dough seems dry, add the additional 2 tbsp of water. If it seems too wet, dust it with a little more atta.
Continue to knead on medium speed until a smooth, dry, and flexible ball of dough forms. It should start wrapping itself around the dough attachment.
Remove the dough, place in an airtight container, and refrigerate until ready to use. (It is nice, but not necessary, to let the dough rest for 10-15 minutes to allow the gluten to develop. It makes it easier to handle.)
Once you are ready to cook the parathas, place spreadable butter, atta for dusting, and a rolling pin near your workstation. Dust your fingers with the dry atta, and take a medium-sized piece of dough (around 90-100 grams) and form into a round ball. Dust the atta on both sides, pressing to form a patty about 3 inches in diameter.
Meanwhile, heat a tawa, heavy-bottomed (preferably cast iron) or flat griddle over medium heat.
While the tawa is heating, roll the paratha out to 5-6 inches in diameter and spread about 2 teaspoon of butter onto the flattened dough. If your butter is cold, dotting pieces of it onto the dough is fine too.
Fold in half from the top to the bottom. Then spread 1 tsp of butter onto the folded dough. Starting from the top, roll down swiss-roll style until a long log is formed. Roll this log, especially from the middle, to make it thinner and as even as possible until it’s about 18 inches long. Then roll tightly into itself from one edge to another. It will look like a cinnamon roll from top. Toward the end, secure the loose end of the dough gently toward the center. Dust both sides with the atta again and roll this out once more until it is around 8-9 inches in diameter. Dust as needed while rolling and do not apply too much pressure.
Place the paratha on the hot tawa. As the bottom of the paratha begins to cook, add 1-2 tsp of butter to the top. Once the bottom is partly cooked (this will take about 10-15 seconds), use a spatula to flip over and add butter on the other side. Cook on both sides for 2-3 minutes, adding butter to dry spots as needed. Once the paratha is golden and crispy on both sides, remove from heat.