Preheat oven to 175°F (80°C) and warm serving plates.

Lightly dust the diced veal with seasoned flour, removing any excess.

In a large frying pan, heat half the butter and oil over medium-high heat.

Sear the veal in batches until lightly golden, turning once. Avoid overcrowding the pan.

Remove seared veal and place on warmed serving dish in the oven to keep warm.

In the same pan, melt the remaining butter and oil over medium heat.

Gently sauté the chopped onion or shallot until softened and translucent, without browning.

Add sliced mushrooms to the pan, sprinkle with lemon juice, and season with salt and pepper.

Cover the pan and cook gently for 5 minutes, allowing the mushrooms to soften.

Remove the lid, increase the heat, and cook until the mushroom juices have evaporated.

Pour in the dry white wine and cook until it is almost completely reduced.

Stir in the chicken stock and whipping cream.

Simmer gently for about 10 minutes, allowing the sauce to thicken slightly.

Check the seasoning and adjust salt and pepper as needed.

At the last minute, return the veal to the pan and gently heat through in the sauce.

Serve immediately.