Heat 1 tablespoon of the oil in a large frying pan. Add the onion and bacon and fry for 4-5 minutes, stirring occasionally, until lightly browned. Set the pan aside.
Cook the spaghetti to pack directions. Meanwhile, beat together the egg, egg yolks and cream and stir in the cheese. Set aside.
Heat the grill to medium-high. Place the tomatoes on a baking sheet and drizzle with the remaining ½ tablespoon of oil. Place under the grill for 5 minutes, until slightly charred and beginning to soften.
Drain the spaghetti and tip into the frying pan with the onions and bacon. Add the grilled tomatoes then pour in the egg mixture. Place over a gentle heat and toss together for 1 minute, until the spaghetti is well coated.
Transfer to warmed plates or bowls, season with freshly ground black pepper (if using) and serve immediately.
Make it veggie: Try replacing the bacon with 275g sliced courgettes – just fry it in with the onion.
Public health advice is to avoid consumption of raw or lightly cooked eggs especially for those vulnerable to infection including pregnant woman, babies and the elderly.