Place a large pan of salted water over a high heat and bring to a boil.
Add the eggs into a small bowl and whisk with a good pinch of pepper.
3 large eggs
Add the spaghetti to the boiling water and cook according to the packet instructions until al dente.
350 g spaghetti
Add a little butter to a large frying pan over a medium heat and add the garlic and the bacon/pancetta together with the sliced courgette/zucchini. Leave to cook for about 5 minutes turning the courgette/zucchini and pancetta over regularly to evenly cook.
50 g unsalted butter, 2 cloves garlic, 3 medium courgettes
When the bacon is cooked and the courgette is coloured and lovely and soft, remove the courgette and the garlic from the pan carefully. Keep the courgette but throw away the garlic.
Reduce the heat to low until the pasta is cooked al dente. When the pasta is cooked, use tongs to move it from the saucepan into the frying pan with the pancetta. KEEP the pasta water for now.
Add 90% of the grated cheeses to the beaten eggs and mix thoroughly.
55 g parmesan, 55 g pecorino
Turn the heat off under the frying pan and leave for a minute for the pan to cool slightly otherwise the eggs will scramble on contact.
Add the egg and cheese mixture to the saucepan and toss quickly or using two wooden spoons, lift the pasta so the everything gets covered.
If the eggs mixture is getting too thick, add a little of the pasta water to thin down to keep everything moist and shiny.
Taste and adjust for seasoning if needed.
salt, pepper
Add the courgettes back to the dish for extra colour, texture and flavour.
Serve immediately in warmed bowls adding a sprinkle of the remaining cheeses and a little more black pepper. Add a little more pasta water if needed but only a little at a time.
Notes
You can use just parmesan if you want but the pecorino adds a lovely additional flavour.