Blend tomatoes, garlic, basil, sundried tomato and black pepper into a paste.
Gently fry the red onion in the olive oil until just golden. Add to blender and liquidise.
Pour the blender contents into a pot and bring to the boil.
Add the tomato paste and thoroughly mix.
Gently simmer, stirring frequently for 10 - 15 minutes and reduce until you have the perfect passata.