To make the dough: Mix the flour and salt in a big bowl. Add in the cut up butter and use your hands to combine. You want to squish the butter cubes into the flour. It takes about 5 minutes and is a bit of a workout! Once the butter is mostly incorporated, add the whisked egg and water (it should be cold). You can use your hands or a spatula to incorporate the wet and dry ingredients until a dough forms.

Split the dough into two disks and wrap with saran wrap/place it in a zip loc and refrigerate it while you do other stuff. You can refrigerate the dough for up to 2 days.

Make the filling: Add the oil to a skillet over medium heat, followed by the onions. Cook the onions down for about 5 minutes. If the pan looks dry, add a splash of water. Add the poblanos, corn, salsa, salt, pepper, cumin and chipotle powder. Mix well and cook for about 10-15 minutes. Taste and adjust flavors as necessary.

When you're ready to bake, take out the empanada dough from the fridge. Lightly flour a clean surface (like your counter or a large cutting board) and roll out the dough with a rolling pin. The dough should be thin, but still thick enough to handle without tearing it. Use a small bowl to cut circles in the dough - simply place the bowl on a section of dough, press and gently shift it side to side. Place the circles on a plate. Then form the remaining dough back into a ball, roll it out and repeat the process until you're out of dough!

Preheat your oven to 375 F.

Spray a baking sheet with cooking spray. Place one of the circles on the sheet and place 1 TBSP of refried beans in the center. Top with 1 TBSP of the filling, followed by a sprinkle of cheese if using. If your circles are on the bigger side, you can add more filling. Fold the dough in half, over the filling, and press the edges together. Use a fork to crimp the edges. Repeat this process until you've prepared each empanada.

Whisk an egg in a small bowl and brush it over each empanada. If you don't eat eggs, you can do this with olive oil or melted coconut oil.

Bake for 20-25 minutes, until they're golden brown. Let them cool before placing them in containers.