Bring the pasta water to the boil. Add a generous amount of salt. Cook the spaghetti until crispy.
Meanwhile, make the tomato and basil salad; chop the cherry tomatoes, tear the basil and toss in a bowl with the ingredients as directed. Leave to marinate.
When the pasta is done, carefully pour off the cooking water and stir in the red pesto.
Roll the spaghetti onto plates and garnish the edges of the dishes with the tomato and basil salad.
Notes
Salt the pasta water generously. Proper seasoning at this stage improves the overall flavour of the dish.
Reserve about ½ cup of pasta cooking water before draining. Mixing a little into the pesto helps the sauce coat the spaghetti more evenly.
Do not overheat pesto after mixing — gentle heat keeps the flavours fresh and prevents the sauce from becoming oily.
Tear basil leaves by hand for the salad instead of chopping to maintain aroma and texture.
Add grated Parmesan, toasted pine nuts or olives for extra depth and variation.