Heat up Extra Virgin Olive Oil and butter in a heavy bottom deep pot. I like using coated cast iron pot.
Once butter is melted, add sliced onions, salt and sugar. Keep sautéing until the onions are completely translucent. It should take about 10-12 minutes on medium heat.
Once onions are completely translucent, add sliced garlic, dry thyme and red chili flakes. Mix well.
Keep sautéing on medium heat to make the onions caramelized. Keep stirring every few minutes to make sure it does not stick to the bottom of the pot. It should take another 15 ish minutes for onions to get caramelized. They should taste sweet and deepen in color.
Once onions are caramelized, add uncooked linguine (broken in half).
Add vegetable broth and soy sauce. Mix well. The vegetable broth should cover the linguine completely. If it does not, add more vegetable broth or water to cover the linguine.
Mix well and cover the pot. Keep cooking linguine in the broth until they are al dente and most of the broth is absorbed.
Add chopped curly parsley and and fresh thyme. Mix well.
Add Trader Joe's onion salt and freshly ground black pepper. Mix well.
Cover the pot for 2-3 minutes.
Add shredded cheese and mix well, making sure there are no cheese lumps and it is all melted well. Adding little at a time and keep mixing works lot better than adding all at once!
Turn the heat off and add heavy cream. Mix well.
Garnish with fresh thyme and parsley if preferred!! Serve it hot!!