Bring veal stock to the boil in a large saucepan, then simmer over medium heat until reduced to 500ml (18-20 minutes).
For braised oxtail, preheat oven to 130C. Heat oil in a large frying pan, season oxtail, add to pan and cook over medium heat until fat renders and meat is golden brown (7-8 minutes), then transfer to a casserole. In the same frying pan, add vegetables and garlic and cook over medium heat until caramelised (5-6 minutes), then add to casserole. Add reduced veal stock, port and spices to casserole and bake, covered, until meat falls from the bone (1½-2 hours).
Remove oxtail, cool, then pick meat from bones (discard bones) and set aside. Strain cooking liquid through a fine sieve into a medium saucepan, cool, skim fat from surface and cook over medium heat until reduced to 500ml and sauce is sticky (7-8 minutes). Add oxtail, season to taste and keep warm.
Increase oven to 200C. Season barramundi to taste. Heat oil in a large oven-proof frying pan, add barramundi fillets skin-side down and cook over medium heat until skin is golden brown and crisp (4-5 minutes), transfer pan to oven and cook until just cooked through (6-7 minutes). Return to stove top, add butter, garlic and thyme, turn barramundi and cook over low heat, basting regularly with pan juices until skin is golden (2-3 minutes).
To serve, divide oxtail among bowls, top with a barramundi fillet, scatter over parsley and serve immediately with beetroot Lyonnaise.
“I enjoy doing variations of surf ‘n’ turf, a lot of people don’t really like it, but I think it works. The earthiness of the barramundi suits something stronger like the richness of the braised oxtail.” — Warren Turnbull