I've eaten overnight oats cold as well as warmed up a little in the microwave; both taste good to me. Served topped with a little granola or chopped, toasted walnuts for extra crunch.
Serve chilled or you can also warm it up in the microwave, too. Top with granola or nuts, if desired.
The recipe makes 3 portions of about 1/2 cup each when packaged in a 8 oz mason jar with some room still on top (i.e., not packed full) as I did with mine, but adjust this if you want 2 bigger (about 3/4 cup) portions instead. To make this vegan, use a dairy-free yogurt in place of the Greek yogurt and agave nectar in place of the honey.