Bring about 6 quarts of water to a boil in a large pot.
Meanwhile, peel the onion and finely chop it. Place the olive oil in a 12-inch skillet, add the chopped onion, and set it over medium heat. Sauté until the onion turns a rich golden color, about 5 minutes.
While the onion is sautéing, peel and coarsely chop the tomatoes.
When the onion is ready, add the ground veal, season with salt and pepper, and cook, stirring often, until the veal is lightly browned, 2 to 3 minutes. Add the white wine and let it bubble for about 1 minute to evaporate the alcohol. Add the tomatoes and bouillon cube, lower the heat to medium, and continue cooking until most of the liquid the tomatoes release has evaporated, 10 to 12 minutes.
While the tomatoes are cooking, slice the flesh of the olives away from the pits and coarsely chop it.
When the tomatoes are ready, add about 2 tablespoons salt to the boiling pasta water, add the fettuccine, and stir until all the strands are submerged. Cook until al dente.
Add the olives to the veal sauce and continue cooking over medium heat until the fettuccine is ready. When the fettuccine is done, drain well, toss with the veal sauce and the butter, and serve at once.