Preheat oven to 285*
In a large dutch oven heat oil on medium high
Pat roast dry and season well with salt and pepper all over
Once oil is hot, sear roast on each side for 3-4 minutes until a brown crust is formed
Once each side is seared and browned remove roast from dutch oven
Add onions, mushrooms, garlic and rosemary to the dutch oven, give a little stir to combine all ingredients
Place roast back into dutch oven atop of other ingredients
Pour beef broth and wine in as well
Roast in oven for 1 hour uncovered
After one hour cover and continue to cook for an additional 3 hours
Roast should be fork tender and break apart easily when done
For mashed cauliflower, cut head of cauliflower into pieces and steam until soft
In high powered blender or food processor and cauliflower and butter, process until smooth and salt to taste
Cut roast against the grain and serve with mushroom sauce atop of cauliflower