Try these variations:
Puttanesca
Prepare recipe, reducing oil to 1 tablespoon. Add 4 chopped anchovy fillets in step 2. Add 400g canned diced tomatoes, ⅔ cup pitted kalamata olives and ¼ cup drained capers at the end of step 2; simmer for 5 minutes until thickened. Season. Add drained pasta to the sauce; toss to coat. Sprinkle with chopped fresh parsley.
Smoked salmon
Prepare recipe, swapping oil for 30g butter. 
Add 4 chopped green onions in step 2 with chilli mixture; cook until softened. Add 150g coarsely chopped smoked salmon and ¾ cup pouring cream at end of step 2; bring to boil. Season. 
Add drained pasta to the sauce; toss to coat.
Broccoli
Prepare recipe. Add 500g small broccoli florets to pan in step 2; cook, stirring, for 5 minutes or until broccoli is just tender and browned lightly. Continue with recipe. Top with grated parmesan.
Pumpkin
Prepare recipe, reducing oil to 1 tablespoon. 
Add 12 fresh sage leaves in step 2 to chilli mixture. Add 505g canned pumpkin soup at the end of step 2; simmer, stirring, for 10 minutes 
or until thickened. Stir in ½ cup grated vintage cheddar. Stir pasta into pumpkin mixture with reserved cooking water to coat. Season. Top 
with extra grated cheddar.
Ingredients
Method
Cook spaghetti in a large saucepan of well-salted boiling water until tender. Reserve ¼ cup cooking water; drain.
Heat oil in a medium frying pan over 
low heat; cook chilli, garlic and oregano, stirring, for 2 minutes or until chilli softens.
Add spaghetti and enough of the reserved cooking water to coat. 
Season to taste.
Serve topped with parmesan.