Combine walnut pesto ingredients and place in the fridge until ready to use.
Heat a frying pan with a little olive oil and fry beef quickly on all sides until browned, but not cooked through. Remove and set aside for later.
Using the same frying pan, add bacon lardons and fry for 3 minutes.
Throw in chopped onions and sautee along with the bacon for approximately 10 minutes or until onions are soft and bacon is crispy, but not dry.
Add carrot and celery. Cook for a further 3 minutes.
Spices: When adding spices the pan needs to be well oiled otherwise they will burn and lose flavours. If needed add a slug of oil to the pan followed by cumin, chilli flakes, cinnamon and star anise. Cook over medium heat for 1 - 2 minutes until spices become fragrant.
Squeeze in tomato paste and cook over low heat until darkened, approx 5 minutes.
Add tinned tomatoes stock and beef back to the pot, combine well, bring to boil then turn to simmer and cover. Let the ragu slowly cook for 2 - 3 hours until beef is super soft and falling apart. If the temperature is too high and your sauce starts to become dry during cooking, add small splashes of water to loosen.
When the ragu is ready, boil a large saucepan of water season with salt. Cook pasta according to the time on the packet instructions.
Drain pasta and stir through ragu sauce. Divide between plates and top with walnut pesto.