Start by adding the rolled oats, chia seeds, maple syrup, salt, and Greek yogurt (if using) into a mason jar or container with a lid.
Pour in the almond milk and stir really well, making sure there are no clumps of chia seeds hiding at the bottom. This step makes all the difference in texture.
Cover the jar and place it in the refrigerator overnight. You can also make it ahead and keep it chilled for up to 5 days.
In the morning, give it a quick stir, add your favorite toppings, and finish with a little extra maple syrup if you like.