1. Cook pasta according to packet directions, then drain.
  2. Heat a small pan and add the olive oil, onion, garlic, mushrooms, snow peas and chilli, fry for 2 minutes.
  3. Add tuna and chicken stock; simmer for a few minutes to reduce.
  4. Combine sauce with the pasta in a large mixing bowl.
  5. Gently toss through the lemon juice and lemon thyme.
  6. Season with salt and pepper to taste.