The DefaultUI already does this.
Code:
if self.isHeader then
self:GetParent():GetParent():OnHeaderButtonClicked(self, self.tradeSkillInfo, button);
else
if IsModifiedClick() then
HandleModifiedItemClick(C_TradeSkillUI.GetRecipeLink(self.tradeSkillInfo.recipeID));
else
self:GetParent():GetParent():OnRecipeButtonClicked(self, self.tradeSkillInfo, button);
end
end
Blizzard_TradeSkillRecipeButton.xml:169
This is what calls the function you noted.