Chop cucumber into small cubes and drain in a sieve while smashing garlic into a paste.
Mix garlic paste with salt and one third of the chopped mint in a bowl.
Stir in lemon juice, olive oil, yoghurt, and drained cucumber then chill in the fridge.
Trim lamb fillets and brown them in 2 tbsp of hot oil in a large pot.
Remove lamb then deglaze the pot with garlic, balsamic vinegar, and red wine.
Add rosemary, mint, stock, and sugar then simmer until the liquid reduces by half.
Season lamb with celery salt and oregano and simmer in the sauce for 5 minutes.
Remove lamb and finish the sauce by reducing it further with lemon juice.
Prepare couscous per instructions, then mix with pine nuts, raisins, herbs, citrus, cumin, and oil.
Boil green beans for 4 to 5 minutes until tender and drain well.
Serve sliced lamb over couscous and beans topped with reduced juices and tzatziki.