Measure all the rest of the ingredients in separate prep bowls. You can combine the onion and garlic powder into one bowl. You do not need to measure the fish sauce at this time. You will drop a dash in the "sauce" directly later.
You will need a 12-inch cast-iron pan or similar-sized saute pan.
Caramelize the Onions
Set the heat at medium-high and add 1 tablespoon of Earth Balance and when that melts, add 1 tablespoon of sunflower oil to the pan.
Once the pan and oil are hot add your shallots and onions.
Season lightly with kosher salt and pepper.
Add the sprigs of thyme and mix the onions to coat with the oil in the pan.
Once the onions begin to soften and become translucent, lower the heat slightly and keep cooking.
The carmelization process will take about 30-45 minutes
During this time, mix the onions frequently. You will start to see them changing color as they cook. You will also see moisture in the pan as the cooking process releases the moisture from the onions.
If the pan becomes dry, which is will about halfway to two-thirds into the process, add a small amount of water to the pan to prevent burning and sticking. About one half cup at a time.
Keep stirring, cooking, and adding water if needed until the onions reach a deep, caramel color.
Chilling the Onions
When the onions are done cooking, remove the thyme and discard, and then transfer to a stainless steel or similar bowl and put in the freezer to cool. You may want to cook them down for 5-10 minutes before you put the bowl in the freezer. I don't but I put them in a huge chest freezer and their warmer temperature will not cause the freezer temp to drop much.
Make the "Sauce"
While the onions are chilling, mix the rest of the ingredients in a bowl to combine. Don't forget to add the dash of fish sauce.
Taste your sauce and decide if you want to add anything more, such as balsamic, Dijon, etc.
Do not add kosher salt and pepper just yet.
When you are satisfied with your sauce, get the onions from the freezer.
Chop the Onions
Empty the onions from the bowl to a cutting board. Using a chef's knife, chop the onions to your desired size. I like them fairly well chopped but any size will work.
Put the chopped onions back in the bowl.
Finish the Dip
Add the "sauce" to the onions, a little bit at a time. Keep adding until you are happy with the consistency. You may, or may not use all the sauce.
Now is the time to taste. Grab one of the potato chips you will be serving with the dip and see how they taste together. You may want to add kosher salt or you may not. You will most likely want to add ground pepper.
You can refrigerate overnight to let the flavors meld, or serve right away.
If you have any dip leftover, store in the fridge for up to a week.