Preheat oven to 450F. Coat shanks with olive oil, salt and pepper. Place on sheet pan and in oven and roast until well browned- About 10-15 minutes. Set aside.
In saute pan, heat 2 Tbsp of olive oil and add mirepoix. Saute until lightly browned. Add garlic and continue cooking 3-4 minutes. Add tomato paste and cook 3 minutes. Add red wine, increase heat to medium high and reduce wine by half.
In a braising pan just large enough to fit all ingredients,add the mirepoix and wine. Add diced tomatoes, chicken broth, demi glace, rosemary and thyme. Nestle in seared lamb shanks. Cover and place in 350F oven. Cook 2-3 hours or until an inserted fork turns easily.
Remove lamb shanks and cool properly. Meanwhile, remove any remaining herb stems and reduce liquid until slightly thickened.
Divide the braising liquid evenly amongst the eight lamb shanks and chill. Reheat together in covered pan for 10- 15 minutes and serve with appropriate starch such as risotto or polenta and fresh green vegetable like haricot verts.