Season beef and place into a Slow Cooker turned on high heat. Add the onions, garlic, Syrah and the liquid smoke. Cover and cook after your Slow Cooker's instruction approximate 6 hours.
If you use a Dutch Oven, Preheat oven 375F, then sear the meat both sites for a few minutes in a little olive oil. Add the liquids, cover the pot and place in the oven for approximate 1 and 1/2 to 2 Hour or until the meat is tender.
In a saute pan heat olive oil and butter, add onions and saute over medium high. Steering occasionally and cook until the onions are dark golden color and caramelized. Set aside.
After meat is tender remove meat and place on a cutting board. Cover the meat and let it rest before slicing. In a medium sauce pan add 1 cup of the cooking liquid, 1/2 cup of Syrah and simmer for 15-20 minutes until liquid reduced by 2/3 rd.
You can serve as a sandwich with Baguette- lettuce leaves- slices of beef brisket - drizzle with the Syrah Pan Juice and top with the caramelized onions.
You can add a few of dried cherries or cranberries for a little extra.