Preheat oven to 375
Heat a skillet over medium heat and add in the finely chopped onion with a sprinkle of salt; cook until softened, then add in the minced garlic clove and cook for about 30 seconds, set aside to cool
Combine the cooled cooked onion, garlic, parsley, red pepper flakes, parmesan, salt, and egg, and soaked bread in a large bowl
Mix together so that the egg is mixed well; the piece of bread breaks up; and everything is well incorporated
Add in the turkey and ground black pepper and use a fork to mix until just combined; being careful not to over mix or the meatballs won’t be tender
Line two baking sheets with aluminum foil and use a small scoop or spoon to scoop out the meat mixture onto the prepared sheets
Bake at 375 for 15-18 minutes depending on their size (you should get about 30 meatballs give or take)
Meanwhile prepare the soup:
Heat the butter and oil in a large heavy pot over medium heat
Once melted add the onion, carrot and celery
Sprinkle with a little salt and allow to soften; about 8 minutes
Add the garlic, thyme, oregano and cook for about 30 seconds; careful not to burn the garlic
Add the chopped kale and allow to soften for a minute or two
Add the vegetable stock, chicken stock, tomatoes, cheese rind (if using) and meatballs
Bring to a slight boil then lower to a simmer for about 20-30 minutes (You can eat it right away, but it does taste better after it simmers a bit and the flavors come together)
Add salt and pepper to taste