If I am creating a salad dressing using lemon juice instead of vinegar, do I use the same amount of lemon juice as I would vinegar and are there standard ratios of oil to acid that you use?

Paul McLoughlin says: Generally the rule of thumb is one part vinegar (or another acid such as lemon juice)/ three parts oil. So yes you could replace the vinegar by lemon juice, the amount is just a guideline and it is up to you to decide what matches your taste preference, also if you use French mustard such as Dijon as a base you might use less acid as it contains vinegar.

How do I achieve a perfect crackling when roasting pig at home?

Jordi Villegas says: The most important part to achieve a perfect crackling skin in a duck or pork is the previous marination. In the case of the pork I marinate the pork with salt, sugar and paprika for 12 hours at equal parts. The salt and the paprika will give the taste to the pork, the sugar will give a very crispy skin when cooked at the right temperature. Cook the pork at low temperature for 2 hours ( 140 degrees) and finish at high temperature for 40 minutes (200 degrees)

I would like to recreate stir-fried egg whites at home, what are some of the tips in preparing that? Can you offer a few quick steps

Man-Sing Lee says: It's not easy to cook good stir-fried egg whites at home as it is easily overcooked or becomes too, as it's easy to for it to be over-cooked or too oily. My recommended steps are:

1. Heat the wok and keep a little amount of heated oil in it
2. Reduce to medium heat, add egg
3. Stir for a while, switch off the stove if temperature of the oil is too high
4. Serve

Tips: Mixture of 300g egg, 300g milk and 1 teaspoon of corn starch makes the perfect egg wash. Stir them with chopsticks. Another important factor is the heat, keep it not too high to make the egg whites silky.</p>