A Summery Salad - Cucumber, Tomato, Avocado Salad

This salad is simple and delicious but requires a lot of fine dicing. It's a great opportunity to develop dicing skills, but if in a rush, not a good recipe for a quick meal.
Please note that the veggies are best when diced into small cubes. It causes that same feeling of plenty that pasta does to me.

1/4 English cucumber, peeled and diced

1 to 2 ripe tomatoes, seeded and diced
1 avocado, diced
1/4 small red onion, diced
1 bunch fresh mint leaves, finely chopped en chiffonade
A few spoonfuls of olive oil
A dash of red wine vinegar
A squirt of lemon juice
Salt and pepper
Boston or Cos lettuce leaves
OPTIONAL Chèvre cheese or feta cheese

1. Dice the avocado first and toss with a squeeze of lemon to prevent browning.
2. Dice remaining vegetables and toss with the chopped mint.
3. Season to taste at the last minute with olive oil, red wine vinegar, lemon juice, salt and pepper. Serve the salad in individual servings in a single lettuce leaf “boat.”
4. OPTIONAL: This is also good with goat cheese or feta cheese scattered on top.