Bake pie crust according to package directions if store-bought. If using homemade pie crust, bake for about 8-10 minutes at 375F, until firm. It should not be “doughey” anymore. Make sure to poke a couple of holes in the bottom and sides before baking so it doesn’t bubble up or crack!
Once it’s baked, set it aside to cool for about 10 minutes. Tip: It’ll cool faster on a cooling rack.
Chop onions and spinach. Set aside.
In a large bowl, gently whisk eggs and half and half to combine.
Add onion, ham, cheese, and spinach to egg mixture. Add salt and pepper and stir gently to combine.
Pour batter into cooled pie crust. It’s okay if it’s warm, but it should not be hot or else the egg will start to cook and the quiche will not bake evenly!
Bake at 375F for 25 minutes and then check if it’s done by inserting a toothpick into the center and seeing if it comes out clean. If not, bake for another 5-10 minutes, checking frequently.
Once it’s done, remove it from the oven and allow it to cool on a cool counter or cooling rack for 10 minutes before cutting.
Once cooled, slice into 8 even slices and enjoy! Store in the fridge for up to 5 days.