Preheat the oven to 450°F.
Line a baking sheet with aluminum foil or parchment paper.
Cut the butternut squash into small, even sized cubes or slices. About 1/8” thick.The thinner, the faster they cook. Toss the squash in olive oil and sprinkle the herbs on the squash and bake for 10-15 minutes or until soft. When the squash is done, remove from heat and let cool. Turn the oven temperature down to 350°F.
While the squash is cooking, sauté the onions in the butter. Heat a small pan on medium heat, add the butter and after it foams, add the onions. Cook on med-low until caramel colored or 5-7 minutes. Stir often. Remove from heat when done cooking.
Take the pie dough and roll into a 9-10” circle. It doesn’t need to be perfect but try to make it round. It is easiest for transferring if you roll out your dough on parchment paper or a cutting board. Once rolled out, place onto a baking sheet. If using premade dough, just place on the baking sheet.
In a small bowl, whisk the egg. Set half the egg aside and add the ricotta cheese to the half in the small bowl. Spread the egg and ricotta mixture onto the pie crust, leaving a 1-2” margin of dough.
Take the cooled vegetables (its ok if they are still warm-just not hot) and layer first the butternut squash onto the ricotta, and then the onions. Now take the edge of the dough and pull up and over the vegetables. You will not cover the vegetables completely but are creating a crust. Once the crust is pulled up, and the vegetable are all tucked in, take the other half of the whisked egg and brush onto the crust. You can sprinkle garlic powder on the crust on now if you choose.
Turn the oven down to 350°F, and pop into oven and bake for 35-40 minutes or until crust is golden brown. Remove from oven. Let the galette stand for 15 minutes before serving. Best if eaten warm.