Preheat oven to 350 degrees (325 convection). Pat beef dry and season both sides with salt and pepper. Heat 2 Tbsp olive oil in a heavy dutch oven over medium-high heat. Add beef and cook until well browed on both sides, about 5-6 minutes a side. Move to a plate and lower heat to medium.
Add remaining oil and onions to the dutch oven. Cook, stirring frequently until the onions soften, about 6-8 minutes. Add garlic and stir, cooking for about 1 minute until garlic is fragrant. Add the red wine and scrape up the brown bits on the bottom of the pan. Add the broth and dry porcini mushrooms. Return beef and any accumulated liquid to the pot (the liquid should be about 3/4 up the sides of the beef). Bring the liquid in the pot to a boil. Cover, and transfer to the oven. Cook 3 hours, turning the beef over halfway through the cooking time. (Add more broth at this time if liquid gets too low, below about 1 1/2 C).
Remove from oven. Beef should be fork tender. Transfer beef carefully to cutting board and tent with foil. Meanwhile, spoon any excess fat out of the pot and using an immersion blender, blend the pan juices and vegetables until smooth (or put in a real blender if you don't have immersion blender, but be careful because its hot and steam needs to release). Add the rosemary and thyme, and simmer for about 5 minutes to thicken the gravy. Add salt and pepper to taste.
Slice the beef into 1 inch thick pieces and put on a plate. Top the beef with the gravy to taste.
Enjoy!