yep,i've paricipated in the construction of one.
it was a two bent great room on a stick frame, with ridge, plate and two purlins each side as i recall. t'n'g from ridge down and overhung plate by a couple of feet.
we ran two by six on edge ridge to plate at either end and across the bottom, perpendicular to the roof pitch. just a big box screwed to the t'n'g using small metal L brackets. inside this went VB and then 5 1/2" rigid foam in large sheets. this material had a shiplap type joint, i think. joints and space around the edges were filled with canned expanding foam. the sheets ran right to the ridge and the gap at the ridge was covered with misc. offcuts and foam.
strapping was 2 x 4 screwed right through everything, shimmed where necessary to meet the stick frame.
lookouts were framed on the front side to allow continuation of the t/g, 2x8 subfascia and support the decorative timber truss at the gable. these were just 2x6 with 2x4 that ran over the 2x6 at the edge ot the timber frame and were screwed right through the foam and in to the t'n'g, just like the roof strapping.
2x6 sub-fascia was attatched at the eaves, again with small metal brackets. i guess this could be either plumb or perpendicular to the roof. perpendicular in this case.
i think steel went directly over all this.