Heat the oil in a large skillet set over medium-high heat. Season the veal with salt and pepper; coat in the flour. Reserve the leftover flour. Cook the veal 2 to 3 minutes per side. Remove from the skillet and set aside. Add the mushrooms, garlic and rosemary to the skillet and cook 3 to 4 minutes. Mix in 2 Tbsp. of the reserved flour; discard the rest. While stirring, slowly mix in the stock. Bring to a simmer; season with salt and pepper. Return the veal to the skillet and heat through 1 to 2 minutes, and then serve.