Heat a little olive oil in a skillet and add the onion, chopped into small pieces. Cook until softened.

After a few minutes, add the cherry tomatoes and cook until they are very soft. While cooking, add a little salt and a pinch of sugar.

Once the tomatoes are ready, add the pesto.

Meanwhile, bring a pot of salted water to a boil and cook the pasta according to the package instructions.

When the pasta is ready, drain it and add it to the skillet with the tomatoes and pesto. Toss everything together to combine.