Ready in 20 minutes
NB: I usually decrease the amount of olive oil to 1/3 cup and use the full 6 tablespoons of balsamic
Assembling the salad:
Soak onions in 1/2 cup red wine vinegar for 30 minutes to decrease sharpness. Tear lettuce into bite sized pieces. Toss lettuce with all but 3 tablespoons of the pine nuts, scallions, 1/2 of cheese, 1/2 of prosciutto, and all of basil.
Making the dressing:
In a medium skillet, slowly cook the garlic in the olive oil over low heat for about 8 minutes, until garlic barely colored. Remove garlic with slotted spoon and reserve. Turn to medium-high heat and add vinegars. Cook a few moments until acid is diffused slightly. Add brown sugar to taste & bubble slowly for 1 minute. Taste for sweet/tart balance and adjust with more balsamic vinegar or sugar to taste. If too sharp, let boil for a few minutes. Stir in reserved garlic and season with salt and pepper.
Top with drained onion and scatter rest of pine nuts, cheese, and prosciutto over the salad. Reheat the dressing, stir vigorously to blend, and spoon over the salad. Serve immediately.