Make Pie Dough:

1. Add the flour, cornstarch and salt to the bowl of a food processor. Pulse 2-3 times until combined. Add in the butter and pulse 5 times.
2. Add the vinegar to the water. With the motor running, slowly pour the water into the flour. The dough should be crumbly and it should hold together when squeezed. Drip in more water and toss together if needed.
3. Empty the flour mixture onto a work surface and divide it into two piles. Quickly form each dough pile together into a rough rectangle shape. If there are any dry spots, drip a bit more water on them and knead together if you have to. Each dough should weigh about 12 ounces. Place each in a piece of plastic wrap and wrap tightly.
4. Using a rolling pin, roll the dough out until it stretches to the corner of the plastic wrap.
5. Refrigerate for at least 2 hours, but preferably overnight.

Make the filling:

1. Heat oil in a medium nonstick over medium heat. Once hot, add diced onion and bell pepper and cook until softened, about 5 minutes.
2. Meanwhile, crack the eggs into a medium bowl along with the heavy cream and a big pinch of salt and pepper. Using a fork or a whisk, beat the eggs until they are completely blended together with the cream.
3. Add eggs to the pan with the onions and peppers, and cook for 2-3 minutes, gently stirring as they set, with a spatula. The eggs should be softly set. Do not overcook the eggs here as they will continue to cook in the oven. Set aside the scrambled eggs to cool off for 15 minutes.

Assemble and Bake:

1. Preheat oven to 400ºF and set a rack in the lower middle part of the oven.
2. On a well-floured surface, roll out 1 pie dough to a rough 11x14” rectangle. Fit the dough in a 9x13” rimmed sheet pan, making sure to press the dough into the sides and the bottom. Roll out the second dough to a 9x13” rectangle and set aside.
3. Once the eggs have cooled to the touch and are no longer hot, transfer them evenly on top the pie dough. Evenly spread the cooked bacon, sausage and shredded cheese on top of the eggs.
4. Placed the rolled dough over the top of the filling, and crimp the edges as desired. Slice a few holes in the top dough to let the steam escape during baking.
5. Brush an egg wash on the top dough. Place the slab pie on a larger baking sheet to catch any butter drips.
6. Bake on the lower rack, for 40-45 minutes until the pastry is golden brown and the filling is bubbling through the holes.
7. Let the pie cool for about 5-10 minutes before slicing.