Step 1

Place water in a bowl large enough to hold both the water and all the dry ingredients and still have room to spare. Mix together dry ingredients in another bowl.

Step 2

Add dry ingredients to water a bit at a time and mix thoroughly to form a dry rough mass.

Step 3

Pour the oil over the dough, mix again to scrape off any dough residue stuck to side of the bowl, and place the rough shaggy dough onto a work surface.

Step 4

Knead the dough for 5-7 minutes.  If the dough is too sticky, place a clean bowl inverted over the dough and wait 30 minutes before resuming.  Return to kneading (just make sure to knead for at least a total of 5 minutes).

Step 5

Place the bowl over the dough once more and let sit for 30-40 minutes to warm up before forming the dough ball.

Step 6

After 40 minutes pull the dough towards its end repeatedly to form a smooth ball.  Pinch the seam side and place the dough ball seam side down into an oiled bowl and cover tightly with plastic wrap.  Refrigerate for at least 12 hours before using.

Step 7

Take the dough out of the fridge 2 hours prior to using. Do not uncover the bowl. Oil the bottom of a 12 by 16 sheet pan (or standard half sheet pan) with 3/8's cup of olive oil. You need to use a lot of oil!

Step 8

Remove the dough from the bowl and place it into the pan. With your fingertips begin pressing the dough into the corners of the pan. You will not be able to do this in one attempt.  Place plastic over the pan and let the dough warm up.

Step 9

After 45 minutes remove the plastic and try to stretch it again to the size of the pan.  Cover with plastic wrap and repeat process one more time until the dough has completely filled the pan.  Cover the dough one more time and set aside.  Preheat oven to 450f and set one rack to the lowest level of the oven and one to the highest.

Step 10

Hand crush the plum tomatoes and drain the juice.  Save the juice for another use.  Add a ½ teaspoon of kosher salt to the tomatoes and set aside.

Step 11

Mince the garlic and add to a bowl with a ¼ cup of olive oil.

Step 12

Remove the plastic from the pan and if required press the dough into the edges.  Right away layer the mozzarella cheese in an overlapping shingle pattern, leaving the outside 1/4 to 1/2 inch uncovered.  Start with a corner.  By pressing the dough down slightly you can lock the dough into the corner.  Make sure the dough is layered completely with the mozzarella slices.

Step 13

Next, add the drained plum tomatoes to the pizza.  You can use 45 degree lines or spoon the sauce all over.  Leave some open areas.  Don’t coat it all.  Take the garlic oil and drizzle 3 tablespoons of the oil and garlic pieces all over the pizza.

Step 14

Place the pizza onto the lowest rack and cook for 12 minutes rotating the pan 180 degrees after 6 minutes.

Step 15

After 12 minutes remove the pizza from oven and check the bottom for browning. If the pizza is well-browned, bake on top rack for 6 more minutes. Otherwise, leave the pizza on the bottom rack for 6 more minutes.

Step 16

After 18 minutes of baking remove the pizza and sprinkle with the oregano and Pecorino Romano cheese. Bake for 2 minutes more on top oven rack.

Step 17

If the Grandma pizza is not crisp enough on top, you can broil for 30-60 seconds.  Watch very carefully though!

Step 18

The total cooking time will be approximately 20-22 minutes.  Let the pizza sit for 5 minutes before cutting and serving.  Enjoy!