First make the tortillas: place the flour, whole wheat flour, oil, baking powder and salt in a large bowl. Add boiling water in small increments and mix through with a spoon or spatula.
Once it starts to come together, use your hand to knead to a smooth dough. I like doing this on the kitchen counter for 5 mins. Add more water or flour to knead if necessary. Set aside for at least 30 mins. Can be made up to a day in advance and refrigerated.
Salsa: grate the tomatoes into a bowl and discard the skins that get left behind. Stir in the onion, chillies and salt. Taste and adjust.
Separate the dough into golf ball sized pieces. Roll in your palms until smooth, then roll out each ball into thin tortillas.
Heat a pan over medium and lightly colour the tortillas on both sides. You’re only looking to half cook them at this stage. Stack one on top of the other in a closed bowl and set aside until you make the filling.
Filling: Use the bottom white and light green parts of the leeks and discard the dark green tops. Add the leeks to a pan with the oil. Season with salt and pepper. Cook until they soften and wilt down, about 5-7 mins.
Add mushrooms to the pan and cook until they soften. Take off the heat and add the grated cheese. Stir for 30 seconds. Transfer to a bowl and let it cool slightly before filling your tortillas.
Whisk the eggs with salt. Wipe down the pan you used to cook the leeks. Lightly scramble the eggs with a little oil. Take off the heat when they're still slightly under.
Assemble: lay out all the tortillas on the counter. Add the leek and mushroom filling to one half of the tortilla. Top with the scrambled eggs.
Fold the other half over to press down firmly to seal them shut. They might open up as they sit but that’s fine. They'll stick together better once you cook them.
Add a little drizzle of oil to a wide pan and cook the tortillas until they are golden in spots and slightly crispy. Press down with a spatula to contain the filling. Flip once and cook the other side. Serve hot with the salsa.