Add the whole milk, sodium citrate, and a pinch of kosher salt to a small saucepan. Bring the mixture to a gentle simmer over medium heat.
Turn off the heat and add the freshly shredded cheddar cheese. Cover the saucepan and let the cheese soften for 5 minutes.
Add the rice wine vinegar and blend with an immersion blender until the cheese sauce is completely smooth and silky. Keep warm until ready to serve.
Heat a large skillet over high heat until very hot. Add the neutral oil and spread the thinly sliced beef into an even layer.
Allow the beef to sear undisturbed until deeply browned and caramelized. Once good color develops, begin stirring and tossing the beef.
Season generously with kosher salt and freshly cracked black pepper.
Push the beef to one side of the skillet. Add the minced garlic and cook briefly until fragrant, then mix it into the beef. Remove from heat and set aside.
Heat a second skillet over high heat and add the neutral oil.
Add the sliced red bell pepper and spring onions. Cook until softened, lightly charred, and caramelized around the edges.
Season with kosher salt and black pepper to taste.
Divide the hot cooked white rice between serving bowls.
Top each bowl with the cheesesteak beef, charred peppers and onions, and a generous spoonful of warm cheddar cheese sauce.
Finish with crispy garlic and serve immediately.