In the bowl of a food processor combine the flour, cornmeal, whole wheat flour, salt and pepper. Pulse once or twice to combine. Add the diced butter and pulse until you end up with small pieces of butter, similar to the size of rice.
In a small bowl, whisk together the one egg yolk and 3 tablespoons ice cold water. Add it to the dough and pulse until the dough comes together. If needed add 1-2 tablespoons more ice water. Turn the dough onto a floured work surface, knead a couple of times and then form the dough into a flat disk. Wrap in plastic wrap and refrigerate for at least 30 minutes.
Meanwhile, heat a large skillet over medium heat, add the olive oil and the garlic. Cook for one to two minutes, until the garlic is fragrant (PLEASE - watch closely!! Don't burn the garlic.). Add the spinach and cook until just wilted. Remove and stir in the artichokes, basil, lemon juice, pepper and salt. Set aside.
Now grab your dough from the fridge. Flour your work surface and roll the dough to about 1/8-inch thick. Transfer to a baking sheet lined with parchment paper. Leaving a 3-inch border around the edges, top the dough with the mozzarella cheese, then the spinach + artichokes mix, then scatter on the blue cheese crumbles and finish off with a sprinkle of pine nuts.
Fold the edge of the dough over the filling. Brush the crust with the beaten egg. Place the galette in the fridge for 15 minutes or until ready to bake.
Preheat the oven to 375 degrees F. Bake the galette for 45-55 minutes or until the crust is golden. Allow to cool 5 minutes and then slice and serve with fresh basil and a drizzle of balsamic reduction if desired. The crust will be crumbly so cut small slices for easier serving.
*Galette dough adapted from my [Caramelized Corn and Heirloom Tomato Galette w/Herbed Roasted Garlic Goat Cheese | https://www.halfbakedharvest.com/caramelized-corn-heirloom-tomato-galette-wherbed-roasted-garlic-goat-cheese/].