This is sort of the counter question to Mezonos bread. At what point does a grain based admixture transition between bread and non bread?
The general position of Sephardic Jewry is that any alteration of taste removes it from the status of bread, such as adding sugar, honey, or large amounts of oil. Here I'm NOT LOOKING to alter the taste per se, but I am looking to make a lower carb recipe by replacing much if the flour with a mixture of something else.
For instance: would pure gluten still allow it to qualify as at least mezonos? Or a mixture of gluten, wheat flour, and chickpea flour allow it to be hamotzi? At what point would the transition (at least from an Ashkenazi perspective) be between bread and Mezonos, and between Mezonos and shehakol?
Additional research that may help. If we consider Pas Haba Bikisnin (PHbK), the primary definition of bread is water and flour. "Adulterating" the water by adding in a rov of non-water (For Ashkenazim, or enough to change the taste for Sephardim) would push an object into PHbK. This is irrespective of the additive being a liquid (oil, juice, possibly eggs, etc.) or a solid (fruit/raisins, sugar, etc.).
Potentially, both the gluten and the chickpea flour might be considered "adulterants." What isn't clear is whether the addition of more flour of another type is considered an adulteration to the water or the wheat flour. The chickpeas, since they operate as flour might be consider to dilute the wheat rather than the water. Gluten, since it is a wheat derivative, may even be rendered completely battel to the rov of flour, rendering the wheat flour volume of the bread effectively higher and allowing you to add in more chickpeas...