Green beans with balsamic vinegar

Another variation on green beans.

1 lb green beans, cooked
chopped country ham or several slices of proscuitto, diced
1/2 red onion
balsamic vinegar
Toasted almond slices

Caramelize the red onion; when almost done, add the ham or proscuitto. Deglaze with (1/3 cup or so?) balsamic vinegar. Let the vinegar cook down until reduced by 2/3. Toss the green beans with this mixture, add toasted almonds, and serve.