Classic Barbecue Vinaigrette Sauce

Prepare the onion: cut off the root end and slice it in half. Peel and cut into large pieces to make processing easier.

Pulse the onion in an immersion blender, if you desire a very fine chop, mixing in some parsley during the process to chop it as well.

Transfer the chopped onion and parsley to a bowl.

Roughly chop the tomatoes (with skin and seeds, if preferred) and add them to the blender.

Add the juice of two squeezed limes (or vinegar, if you prefer a more acidic flavor) and plenty of extra virgin olive oil to the mix.

Season with salt to taste and, if necessary to balance the lime's acidity, add a little sugar.

Taste and adjust the seasoning before serving.