Bring a large casserole with water to a boil and add 1 tbsp of sea salt flakes. Cook the pasta until al dente (tender, yet still firm and chewy), this takes approximately 6 minutes. Drain the pasta and reserve 1-2 cups of starchy pasta water.
While the pasta cooks, add the olive oil to a heavy-base castiron pan over medium-high heat and fry the bacon until golden and crisp. Add the garlic and cook for 30 seconds before turning off the heat.
In the meanwhile, whisk together the eggs and grated parmesan or pecorino. Season with salt and pepper, keeping in mind that the cheese may be salty enough. Add ½ cup of the reserved pasta water to the egg and cheese mixture and beat thoroughly.
As soon as the pasta is cooked, add it to the hot pan with bacon and garlic. If the pan has cooled down, heat the pan until the bacon and pasta begin to sizzle, switch off the heat completely and proceed to the next step.
Pour the cheese and egg mixture over the pasta and bacon. Now, working fast, continuously lift and toss the pasta using two forks or utensils. You want the egg mixture to emulsify and slightly thicken into a smooth, creamy sauce that coats the pasta without scrambling the eggs. This only takes 3-5 minutes and the residual heat of the cooked pasta and pan should be enough to cook and thicken the sauce. If the mixture is too sticky or dry, slowly add some more pasta water and continue to toss until the desired consistency is reached.
Sprinkle over the crispy bacon and garlic, freshly ground black pepper, and some more parmesan cheese. Serve immediately.
To warm the pasta, heat over medium heat while adding in a little more pasta water to make it creamy again.