In a large skillet over medium heat, melt the butter and olive oil. Stir in the onions (yes it’s a lot of onions!), reduce the heat to medium-low, and cook for about 10 minutes, stirring every few minutes. If you ever notice the onions are browning or burning, reduce the heat.
Reduce the heat to low and continue to cook the onions until they are deeply golden brown and jammy, about 40-60 minutes, stirring every 5-10 minutes or so. The longer the better.
As you get towards the end (at about 40 minutes) when the onions are caramelized, you may need to stir more frequently so they don’t burn. At the very end when they are deeply caramelized, stir continuously.
When they are done (golden brown and jammy), stir in the balsamic and soy sauce to deglaze the pan, scraping up any stuck bits. Turn off the heat and season with salt and pepper, to taste.
Let the onions cool off a bit. In a medium bowl, stir together the yogurt, sour cream or cottage cheese, soy sauce, garlic or onion powder, and lemon zest. Stir in the caramelized onions and scallions. Season with salt and pepper, to taste (amount of salt depends on how salty your onions are, use your judgement).
Serve topped with more herbs and black pepper with your chip and veg of choice.