01 -
Add the flour and salt to your food processor and pulse a few times to mix. Toss in the cold butter and pulse about 15 times until you get a crumbly texture that looks like coarse sand. In a separate small bowl, whisk together the egg yolk and cold water, then pour it into the processor. Pulse just until the dough starts clumping together in chunks—don't let it form a smooth ball or you'll overwork it.
02 -
Dump the crumbly dough onto a lightly floured counter and gather it together with your hands to form a ball. Flatten it into a disc shape, wrap it tightly in plastic wrap, and pop it in the refrigerator for at least an hour. You can make this up to 3 days ahead if you want to get a jump on things.
03 -
Take your chilled dough out of the fridge and let it sit on the counter for about 10 minutes to soften slightly. On a floured surface, roll it out into a circle that's roughly 3 inches bigger than your pie dish and about ⅛ to ¼ inch thick. Carefully drape it over your pie plate, gently pressing it into the bottom and up the sides without stretching. Trim the excess dough with kitchen scissors, leaving about 1½ inches of overhang, then crimp the edges however you like. Slide it back into the fridge while you prep the filling.
04 -
Heat your oven to 425°F. Warm the olive oil in a large skillet over medium-high heat. Crumble in the ground beef and break it up with a wooden spoon as it cooks. Let it brown nicely for 7 to 10 minutes, then drain off any excess grease.
05 -
Toss the panko breadcrumbs, tomato sauce, diced onion, green pepper, minced garlic, salt, oregano, and black pepper into the skillet with the beef. Stir everything together and cook for about a minute until heated through and fragrant. Spread this savory mixture evenly into your prepared pie crust.
06 -
In a bowl, whisk together the milk and egg until smooth. Stir in the Worcestershire sauce, salt, dry mustard, and shredded cheddar cheese until everything's well combined. Pour this cheesy mixture over the beef layer, spreading it out evenly so every bite gets that gooey goodness.
07 -
Slide the pie into your preheated oven and bake for 30 minutes, or until the cheese is bubbly and golden and the crust is beautifully browned. If the edges of the crust start getting too dark before the filling is done, just tent them with a little aluminum foil. Let the pie rest for about 5 minutes after baking before slicing into it.