Mortar and Stucco over insulation

I am curious if after putting up my chicken wire lathe if I could use a premix mortar for the first/scratch layer, and when it is cured after a week or so that I could finish with stucco mix. My plan for the final is to tile over the stucco and grout it to seal.
My big issue is that it looks like it will take weeks for me to get stucco mix locally (Albany Oregon), so it would push me back into August before I could start baking. I plan on using the oven pretty much year around for a weekly bake of artisan bread.
I have plenty of the Portland cement, fire clay, silica sand and lime, and could use them if there is a formula to combine three or so to provide something other than refractory mortar. (Leave out the fire clay? Maybe lime?)