### Instructions:
1. **Combine Dry Ingredients:** In a jar with a tight-fitting lid (a mason jar works perfectly) or a small bowl, combine the rolled oats and chia seeds.
2. **Add Wet Ingredients:** Pour in the milk, Greek yogurt (if using), sweetener, and vanilla extract (if using).
3. **Stir Thoroughly:** Stir everything together really well, making sure there are no clumps of oats or chia seeds stuck at the bottom. You want all the ingredients to be fully incorporated.
4. **Cover and Refrigerate:** Place the lid securely on the jar or cover the bowl tightly with plastic wrap. Store in the refrigerator for at least 4 hours, or preferably overnight. This allows the oats and chia seeds to soak up the liquid and become soft and creamy.
5. **Serve and Enjoy:** In the morning, give your overnight oats a good stir. If the mixture is too thick, you can add a splash more milk to reach your desired consistency.
6. **Customize with Toppings:** Now for the fun part! Add your favorite toppings. Get creative with fresh fruit, a sprinkle of nuts for crunch, a dollop of nut butter, or a dash of cinnamon.
7. **Grab and Go:** Enjoy your delicious and healthy breakfast straight from the jar, or transfer it to a bowl. It’s perfect for a quick and nutritious start to your day, whether you’re at home or on the go!
### Short Tips:
* **Don’t use instant oats:** They will become mushy. Rolled oats provide the best texture.
* **Meal prep in advance:** Make a few jars at once for a week of easy breakfasts.
* **Experiment with flavors:** Add cocoa powder for chocolate oats, or a pinch of pumpkin pie spice for a seasonal twist.
* **Layer your toppings:** For a pretty presentation, add a layer of fruit at the bottom before adding the oats, then more toppings on top.
* **Adjust sweetness:** Taste before adding all your sweetener; you might need less than you think, especially if using flavored yogurt or sweet fruit.
