Preheat the fryer to 180˚/350˚F. If you don't have a frying pan, you can use a saucepan, just make sure you don't put too much in at once.
Take a large bowl and pour the batter into it. Mix the flour, beer, herbs and Parmesan together. Whisk for a while and add salt and pepper to taste.
Clean the onions and cut them into thick rings. Not too thick but not too small. About half a centimeter per ring. Use a sharp knife or a good mandolin with adjustable blades
Using a wooden skewer, slide one onion ring at a time through the batter and carefully place it into the hot oil.
Fry the onion ring for 2-3 minutes or until golden brown. Turn halfway through.
Place the fried onion rings on a piece of paper towel and repeat the process with all the onion rings. Depending on the size of your fryer, you can of course fry more than one at a time. Just make sure they don't stick together.
Make the dipping sauce by mixing the ingredients together. Serve with the hot onion rings.