In a large liquid measuring cup or bowl, stir together all of the ingredients for the overnight oats. Cover with plastic wrap, and place in the refrigerator for at least 6 hours or preferably overnight. Stir before serving.For the compote: if you're using fresh berries, mash the berries in a small bowl. Microwave for one minute. If you're using frozen berries, microwave for 2 minutes and then mash the berries up. Stir in the chia seeds. Microwave for one more minute, and then let cool slightly. Serve with oats.If you prefer to eat your oats warm, cover with plastic wrap and microwave for 1-2 minutes, or until warmed through. You may want to add another splash of non-dairy milk if you don't want the oats to be super thick after reheating.