Add remaining oil to the potato saucepan, and heat on low. Add potatoes and toss gently until coated. Add spinach in 4 batches, gently tossing so it wilts in the heat from the potatoes. Add lemon juice. Season lightly; stir gently to mix. Cover and keep warm while you make the sauce.
Return the frying pan to the heat and add wine. Heat to boiling, then stir vigorously to dislodge any browned bits. Boil until syrupy, about 1 minute, then season lightly. Remove from the heat and add remaining butter. Stir until melted.
Scatter mixed herbs over the veal; drizzle with sauce. Sprinkle lemon zest over the potatoes and spinach. Serve the vegetables alongside the veal, with lemon wedges for squeezing.
Recipe Notes
Per serving: 311 calories, 28 g protein, 9 g total fat, 3 g saturated fat, 82 mg cholesterol, 28 g carbohydrates, 4 g fibre.