To make the dough, combine flours and salt in a medium bowl and mix well. Using a pastry blender or your fingertips, blend butter into the flour mixture until it’s roughly the size of small peas.

In a separate small bowl, whisk together egg and water. Pour over dry ingredients and mix with a fork until dough begins to come together. If still shaggy, add additional water to help the dough come together, 1 tablespoon at a time. Dump out onto a well-floured surface. Knead dough a few times and carefully gather together into a ball. Wrap in plastic wrap and place in the refrigerator to chill for one hour.

While the pastry dough is chilling, preheat the oven to 425. Line a baking sheet with parchment paper. Chop up your cauliflower into small florets. Place into a bowl and toss with a tablespoon of olive oil and salt and pepper. Place florets onto the baking sheet and bake for 20-25 minutes, until just fork tender. Turn oven down to 400.

While the cauliflower is roasting, mix the corn, black beans, cheese, onion, cumin and chili powder. When the florets are done, add them and mix well. Put the mixture to the side.

When the pastry dough is ready, put it onto a lightly-floured surface and divide into ten equal pieces. Roll each piece into a ball. One by one, roll each ball flat, into a circle about 5-6 inches in diameter. Place 1/3 cup of the filling onto the circle and fold over to form a half-moon shape. Pinch the sides together to seal. Place them onto the same baking sheet you used before. When all ten are made, poke a few holes into the top of each and brush them with the egg wash and then bake them for 25-30 minutes, until turning golden on top.