Add the 2 tablespoons coconut oil and 2 tablespoons maple syrup to an 8×8 baking pan. Put in the oven for 2-3 minutes, until oil is melted. Set aside.
Cut the rhubarb and arrange in a pattern in baking dish. Be careful as dish is hot still. You can also cut it in 1″ pieces and toss them in and it will be fine, just not quite as pretty.
In a large bowl, mix the flax seed, cornmeal, flour, baking powder, baking soda and salt.
Add the milk, maple syrup, coconut oil and lemon juice. Mix until well combined.
Carefully pour into the pan on top of the rhubarb so as not to disturb your pattern. The oil/maple mix will come up around the sides, this is expected – it gives the cornbread a nice crispy edge.
Bake 30-35 minutes, or until cornbread is deep golden in color and a toothpick in the center comes out clean.
Let cool 8-10 minutes. Run a knife around the edges, then carefully turn out of the pan onto a plate and let cool completely.