Novel concepts for efficient compact spectroscopy are extensively researched due to their fundamental applications in prominent fields such as biology, pharmaceutical, chemistry, physics, and environment. Here we aim to introduce such a concept with potentially unprecedented, to the best of our knowledge, resolution in the impinging radiation's spectra and azimuth. Though it can be employed in various spectral regions, we exemplify the concept in the mid-infrared, in which its advantages are paramount and have yet to be established industrially. The concept is based on the design and instrumentation of optical absorption spectral tuning (or sensitivity) to the azimuthal component of light impinging on specifically-designed metamaterials. We exemplify the concept with vacuum-wavelength (λ0) scale thick metamaterials optimized for perfect photo-absorption inside an embedded λ0/200 ultra-thin layer of lead telluride. We propose and analyze two small-footprint system designs to instrument the spectral-azimuth-angle tuning for spectrometry. The first is based on a single or few spinning metamaterial layout elements (pixels), and the second, to avoid spinning, follows a fixed focal-plane-array approach. The latter exploits the inherent variations in the local azimuthal-incidence angle instead of the typically utilized slightly varying polar angles. While low absorption is the Achilles heel of conventional mid-infrared photodetector spectrometers, the optimized pixels, in addition to their unique spectral-azimuth-angle tuning functionality, provide giant absorption enhancement, which facilitates higher resolution and even smaller in-plane form factor. The highlighted concept opens an additional dimension to encode and decode spectral information, which yields profound advantages over conventional designs as diffraction gratings based.