Using your hands, form the beef into large meatballs. It’s OK if they are not all the same size. Set aside.
Preheat a sauté pan or Dutch oven over medium-high heat for 5 minutes. Add avocado oil and heat until shimmering. Add the meatballs and cook until browned, around 6 minutes. Flip and brown the other side, around 6 more minutes. Reserve the fat in the pan and transfer the meat to a bowl. Set aside.
Lower the heat to medium and add the garlic and anchovies. Cook, stirring, for 2 minutes, or until fragrant and golden. Add the carrot, onion and celery. Season with a pinch of salt and cook, stirring, until softened, around 8 minutes. Add the tomato paste and stir to combine.
Return the browned meat to the pot and crumble it using a wooden spoon or potato masher. Add the chicken stock, thyme and bay leaves. Stir to combine, and bring to a simmer. Season with 1 teaspoon salt and 1/4 teaspoon pepper, cover with a lid, reduce the heat to low and cook, stirring occasionally, for 60 minutes. You can cook it for less time but it won’t allow for the beef to soften or the flavours to come together.
Taste the ragu for seasoning and adjust with salt and pepper as desired.
20 minutes before serving, bring a large pot of water to a boil. Season with 1 tablespoon of salt and cook the pasta according to package instructions. Drain the pasta, reserving ½ cup of cooking liquid.
Add 2 cups of sauce and the reserved pasta water to the drained pasta and toss to combine. Plate the pasta in individual serving bowls, spoon over a bit more of the ragu.