In a medium bowl, whisk together eggs, milk, ground flaxseed/chia seeds, sugar, coconut oil until well combined. Add the steel cut oats, cinnamon and salt and stir to combine.
Pour the mixture into a 8×8 or 9×9 pan. Cover the pan loosely with foil and bake for 30 minutes. Uncover the pan and bake an additional 25-30 minutes until golden brown (55-60 minutes total).
Serve hot, scooped into bowls, or let cool for 10 minutes and cut into squares. Store in fridge for up to 5 days.