1 5-oz. can albacore tuna packed in olive oil (do not drain) $2
1/4 medium red onion, sliced very thinly $0.50 for a whole onion
1 tablespoon capers, drained $2 for a 4-oz. jar
about 10 cherry or grape tomatoes, halved $3.50 for a pint
1 small handful fresh flat-leaf parsley leaves, chopped $1 for a bunch
1 tsp balsamic vinegar Pantry
salt and freshly-ground black pepper to taste Pantry
Total Cost of Ingredients $9