In a large fry pan heat 1 tablespoon olive oil over medium heat.
Add onion and garlic, sauté for 2 minutes or until onion is just translucent and garlic is fragrant.
Transfer onion and garlic mixture to a heat-proof mixing bowl. Set aside.
Return pan to a medium heat and add halved cherry tomatoes. Cook for 2-3 minutes or until they just begin to soften and juices are released. Remove from heat.
Transfer tomatoes to the bowl with the onions.
To the mixture, drizzle over balsamic vinegar and mix well.
Season with salt and pepper.
Stir through chopped basil. Leave mixture to marinate for 10 minutes.
In the meantime, cook spaghetti according to packet instructions. Reserve and set aside 1 cup cooking water.
Heat same fry pan over a medium heat, add bruschetta mixture back into the heated pan.
Drain cooked spaghetti and add to pan. Gently mix to combine. Adding any reserved pasta water if needed to help combine or if spaghetti is too dry.
Add bocconcini and cook until everything is heated through.
If serving with crunchy bread, grill it just before serving, recipe below.
Remove spaghetti from heat and serve up.
Garnish with fresh basil, a drizzling of olive oil and grilled bread.