At this point, add minced garlic and allow the garlic to lightly caramelize, then deglaze the pan with a splash of white wine (a few tablespoons).
Continue to stir the onions, and be patient, as this process takes 30-40 minutes. As the onions begin to reach a point where they’re going to start getting crispy, add a splash of water and continue to stir. Do this as often as is necessary, throughout the cooking, until the onions are soft, and a deep golden brown color.
When the onions are cooked, and golden brown, lower the heat and add a drizzle of balsamic vinegar (about a tablespoon in total).
When the onions are done, check for seasoning, add salt and pepper as needed, then set them aside until your frittata is ready.
Start by whisking your eggs just enough so that they’re a relatively even consistency. Season the eggs with salt and pepper, mix in chopped basil, then cook your eggs in a bit of olive oil, on medium heat.
When one side is done, place a plate over the pan (carefully as it’s hot) then invert it to transfer the frittata to the plate. The uncooked side is now resting on the bottom of the plate, and the frittata can be slid back into the pan to finish cooking.
When the frittata is done, place it on a plate, then add your onion jam, sour cream, basil, and chopped chives. Serve and enjoy.