- For braising liquid, heat oil in a small stockpot over medium heat. Add onion, carrots, celery, garlic, and rosemary and caramelize, 5–10 minutes. Deglaze with wine and cook another 5 minutes. Add beef stock and simmer on medium heat for about 30 minutes or until reduced by one quarter. Set aside.
- For beef cheeks, preheat oven to 350 degrees. Heat oil in a large skillet over medium heat. Season beef cheeks generously with salt and pepper and brown, a few at a time.
- Remove cheeks and place in a small braising dish. Cover cheeks by half with braising liquid and cover pan with foil. Braise in oven for 1½–2 hours, until very tender. Remove cheeks from liquid and keep warm.
- Skim fat from surface of remaining liquid and keep liquid warm. In a large sauté pan, cook onion in a little butter until softened and translucent. Add beef cheeks, black-eyed peas, and remaining cooking liquid to pan and simmer, about 2 minutes. At the very end, fold in baby spinach just to wilt. Serve immediately over potato purée.
- In a small pan, simmer cream with rosemary for about 5 minutes. Remove rosemary and keep cream warm.
- Place potatoes in a pot and cover with water and a pinch of salt. Boil until knife tender, strain, and push through a ricer into a large bowl. Immediately add butter and hot cream and mix until smooth and creamy. Adjust seasoning with salt and pepper and keep hot.