With the rack in the middle position, preheat the oven to 200 °C (400 °F).
Insert eight sage leaves all around the roast under the strings. Season with salt and pepper. In an ovenproof skillet, brown the roast in the oil. Add the lemon zest and garlic and roast in the oven for about 25 minutes or until a thermometer in the centre of the roast reaches 52 °C (125 °F). Remove the roast from the skillet and set aside on a plate for about 10 minutes. The internal temperature of the meat should climb to 55 °C (130 °F) for medium rare.
Sprinkle the flour in the skillet and mix thoroughly. Add the broth, lemon juice and the remaining sage leaves. Bring to a boil, whisking constantly. Reduce by half. Strain and adjust the seasoning.
Meanwhile, in large skillet, brown the bell peppers and onions in the oil until tender. Add the tomatoes, parsley and lemon juice and cook for 1 to 2 minutes.
Slice the meat. Serve with the vegetables and sauce.
Recipes with the "Healthy Pick" stamp have been evaluated by a registered dietitian member of the Ordre professionnel des diététistes du Québec.