$p$-harmonic functions by way of intrinsic mean value properties

Let $\mathrm{\Omega }\subset {\mathbb{R}}^n$ be a bounded domain satisfying the uniform exterior cone condition. We establish existence and uniqueness of continuous solutions of the Dirichlet Problem associated to certain intrinsic nonlinear mean value properties in $\mathrm{\Omega }$. Furthermore we show that, when properly normalized, such functions converge to the $p$-harmonic solution of the Dirichlet problem in $\mathrm{\Omega }$, for $p\in [2,\mathrm{\infty })$. The proof of existence is constructive and the methods are entirely analytic, a fundamental tool being the construction of explicit, $p$-independent barrier functions in $\mathrm{\Omega }$.