As a seasoned IT professional with extensive experience in Linux, network administration, and system administration, I believe I'm the ideal fit to resolve your Linux Mint 21.3 boot issue. My knowledge of UEFI systems, combined with my expertise in troubleshooting bootloader issues makes me confident that I can help get your system up and running smoothly.
Moreover, my relevant experience with Linux Mint 21.3 Cinnamon and recovery methods provides me with an in-depth understanding of potential pitfalls and effective strategies for a successful system restoration. I've worked on various projects involving operating system repairs using live USBs, with boot-repair and gparted being part of my regular toolkit. Thus, your project aligns well with my skill set, which will ensure efficient problem-solving without exceeding the budget.
My commitment to delivering quality service and exceeding customer expectations has been integral to my career. Rest assured, I'll invest myself fully in rectifying your boot problem and ensuring an optimized performance for your Linux Mint system. Let's get back to smooth sailing together!