Heat 1 teaspoon olive oil in the pot over medium heat until very hot. Add the onion and cook for 4-6 minutes until golden brown and beginning to soften.
Add the carrots and cook for 8-9 minutes, stirring regularly, until they begin to soften. Add the garlic and cook for 1 minute or until fragrant.
Pour in the stock or wine and scrape up any browned bits stuck to the bottom. Bring to a boil for 5-6 minutes until reduced slightly.
Add the tomatoes and season with salt, pepper, crushed red pepper, and a pinch of sugar.
Add the meatballs to the sauce. Bring to a boil. Cover and reduce the heat to low. Simmer, stirring periodically, for 45 minutes.