Pound veal scallops, dredge in a mixture of flour, salt, and pepper, shake off excess, set aside. Heat 2 tbsp each of olive oil and butter in medium hot skillet. Brown scallops, two or three at a time, about 2 minutes per side until golden brown. Set aside.
Drain all but a bit of the oil from the skillet and add 1/2 can beef stock. Bring to a boil. Using a spatula or metal whisk, stir in all the dried flour sticking to the skillet, then keep stirring until the liquid reduces and thickens. Remove from heat and add the scallops, placing a thin lemon slice atop each one. Cover the skillet and cook scallops over low heat 10-15 minutes.
When the scallops are done, transfer them (with or without the lemon slices — see note below) to a heated platter or casserole and place in oven on warm. Add remaining beef stock to the skillet, bring to a boil, and stir as the liquid reduces. When the liquid thickens, add the juice of 1 lemon (or 1-2 tsps of lemon juice), stir again. Add 1 tbsp butter and stir it in until melted.
Take the scallops from the oven and pour the liquid over them. Serve.
If you have time, use whole lemons. For the thin lemon slices, pick out the seeds before placing them on top of the scallops. When the scallops are cooked, you can leave the cooked lemon slices on top of each scallop, or, if you don’t like the limp look of cooked lemon slices, discard them and add fresh lemon slices to the dish when it’s ready to serve.
Using chicken stock instead or beef stock gives the dish a lighter flavor.