Chop the pancetta into small cubes and place in a non-stick frying pan. Heat the pancetta over a low heat for about 10 minutes, until the fat has melted and the pancetta starts to brown.
In the meantime, boil the eggs to your liking. Mix the mayonnaise, crushed garlic and lemon juice to make the salad dressing.
To serve, arrange the lettuce on 2 plates, add the halved cherry tomatoes and sliced onion. Season with salt and pepper. Top with the browned pancetta and boiled egg, then drizzle with the dressing and serve immediately.