Savory Cake

My first post on my first-ever blog and I don't have a clue how to go about doing this so I'm just going to make it up as I go.
The problem: someone wanted to do a mousse roulade. A simple task. Make a biscuit roulade, fill it with mousse and roll it up.
Problem solved.
Problem not solved... they want a mushroom mousse rolled in a not-sweet "cake".
Ok, leave out the sugar. Oh, you don't want a rubber cake.
Hmmm.
Well, after some thinking, some guessing (of both the educated and not-so-educated variety) and a late night experimenting I came up with a solution. I'm not claiming it's the only solution or even the best solution but a solution nonetheless. The result is a completely neutral "cake" that is not at all sweet and can be flavored as required for the task at hand. Fold in some chopped herbs, some minced sun dried tomato, lemon zest, minced olives, vegetable powder, whatever makes you happy. The result is flexible, rolls easily without cracking and is not rubbery. Is it as tender as the sweet versions? Maybe not... but it's pretty close.
I plan to continue to refine this recipe in the future and welcome anyone else interested to join in or make suggestions but, for now, I'm pretty happy with it.


Savory Biscuit Roulade

180g egg white
120g egg yolk
40g flour
60ml warm water
30g melted butter (brown butter would probably be nice, didn't try it)
7g salt
14 g sugar
1.4g xanthan
2.5g methylcellulose, SGA-7C

Mix water, salt, butter and flour to just smooth. Whip whites to frothy, add combined sugar, methylcellulose and xanthan and whip on high to almost stiff. Beat egg yolks to pale. Mix in flour paste. Mix in part of the whites. Fold in remaining whites and spread on lined, sprayed and floured pan. Bake 220c (425f) 'til done (just under 15 minutes in my oven on an 18"x12" pan). Cool in pan covered with damp cloth. Trim edges and have fun.

Now to my theories, which I confess were based on my own ideas and experiences and have no scientific value whatsoever...

Theory 1: methylcellulose would help stabilize the meringue during whipping and even more so as it heated until the structure set enough to support itself.

Theory 2: xanthan is commonly used in gluten-free baking to help with texture which led me to believe that it may help with texture here, which would take a hit from the loss of sugar, as well.

I have nothing scientific to offer as to whether either theory is correct, all I can point to is the results.