Sift together the flours, baking powder, baking soda, salt, and sugar (if using sugar).
In a medium-size bowl, beat together the eggs, buttermilk or yogurt and milk, oil, vanilla, beet purée and honey or agave nectar (if using). Quickly whisk in the flour mixture and fold in the chia seeds.
Heat a large skillet or griddle over medium-high heat and brush with butter or oil.
Drop the pancakes by the cup onto the hot pan.
Cook until bubbles break through and turn the pancakes.
They will be quite moist so make sure to wait long enough so that they don’t fall apart when you turn them.
Cook for 1 to 2 minutes on the other side, until lightly browned.
In hot pan toss all the ingredients except spinach, for 2 minutes in 1 tsp oil.
Season and keep it aside
Place a pancake and top it with fresh spinach.
Top it with the filling and place another Pancake on top.