Add the pasta to a large saucepan of boiling water and simmer until just done, 7-8 minutes approx. Drain but keep a few tablesp. of the cooking water. This will help the sauce cling to the pasta and adds a certain creaminess. In a large pan cook the bacon in hot oil until crisp. Stir in the chilli and 1-2 tablesp. of the cooking liquid. Remove from the heat.
To make the Pesto:
Whiz the basil, pinenuts, cheese and garlic together in the processor. Add the oil gradually.