In a small saucepan over medium heat, add the blueberries, maple syrup, lemon juice, and a splash of water. Cook for 5–7 minutes, stirring occasionally, until the berries break down and release their juices. Lightly mash with a fork for a jammy texture. Let cool slightly.
In a large bowl, whisk together the milk, Greek yogurt, maple syrup, vanilla, and salt until smooth.
Stir in the oats, chia seeds, and ground flaxseed until well combined.
Add the blueberry compote and gently mix to combine.
Divide into 4 jars or containers, cover, and refrigerate for at least 4 hours or overnight.
Stir before serving. If the oats have thickened too much for your liking, add a splash of milk to loosen to your desired creamy consistency.
