Country salad, Spanish potato salad

Ingredients

• 4 large potatoes cooked and cut into bite-size pieces
• 1 onion cut into small squares
• 1/2 red bell pepper, diced
• 1/2 green bell pepper, diced
• 1 tomato, diced
• 1 can of canned natural tuna
• 15 green or black olives cut in rounds (pitted)
• 2 boiled eggs, chopped
• 6 tablespoons olive oil
• 4 tablespoons white wine vinegar
• Chopped fresh parsley for garnish
• Salt and pepper to taste