When I boil pasta it becomes sticky and lumpy. I add oil and salt to the water and put the pasta noodles in only after the water starts boiling. Please tell me what is wrong?
Sticky pasta is usually due to the pasta noodles themselves being cooked for too long or cooked in too little water. In NIGELLISSIMA Nigella has many wonderful pasta recipes and advises that pasta should be cooked in generous amounts of salted boiling water. The pasta should be able to move around a little in the water so if you are cooking larger quantities of pasta then you will need a large saucepan or stock pot. If you have enough water then oil should not be necessary. She also suggests that you should start to test the pasta 2-3 minutes before the end of the cooking time on the package so that it does not overcook. Take a piece of pasta out with a pair of tongs, let it cool slightly then taste it - the pasta should still be firm though not hard or chalky in the centre. If it is under done then cook for 2 minutes longer and check again. If you are cooking fresh pasta then start testing it as soon as the water comes back to the boil as fresh pasta cooks much more quickly.
Pasta can also become sticky when mixed with a sauce, so Nigella suggests that before draining the pasta you scoop a cupful of the pasta water out of the pan. You can then add splashes of the pasta cooking water to the pasta and sauce if the dish looks too dry. The pasta cooking water can also be a component of the sauce itself - we suggest trying Nigella's Yellow Spaghetti or Spaghetti With Marmite to see how much difference using the pasta cooking water can make to a sauce.