I dont think it can be done in an Ngon, but there is a way to create such a surface without triangles or quads, or lots of triangles.
Just add a circle, but stay in edit mode; select all its points, then press D to duplicate the circle, or while staying in edit mode just add another circle through the menu. Do this for as many times you want. But dont leave edit mode, also add a square on top and bottom.
Next connect the circles so you get something like below you do this by selecting a 1 point from two circles and press F key
also connect the string of circles to the outer cube with a line by pressing F key
Now next step (for which i use circle select to select edges), i first select the center part to fill , these are parts of the circles i select not the whole circle, as this was devided by the previous created edges… then press F to create a surface
I repeat it one more time for the other edges and create again the field by pressing F, below you see the second area as still selected.
There are no quads and neither there are a bunch of triangles, while you could still select circle edges to extrude
Next on top and bottom of your circle grid add a square, but stay in edit mode dont leave edit mode.