I use a 0.25L jar and for each jar, this is my base recipe:
1/8 cup rolled oats
1/8 cup Greek yogurt
about 1/4 cup milk
1+ tsp chia seeds
I find this amount just right for one serving. After you have the four basic ingredients mixed together, you can add whatever fruits, flavoring, sweetener you want. So far, we've tried adding strawberries (with nothing else) and blueberries (with 1 tsp maple syrup). Sometimes the kids have a small side dish of their cereal of choice to eat along with this.
If we are not able to finish a jar, we simply put the lid back and pop the jar in the fridge to eat later as a snack. I’m not a big fan of oats, but there are so many things I love about this. It’s so easy to prepare. It’s healthy and best of all, it’s yummy.