Start by roasting the red bell pepper in a preheated oven at 400 degrees F (200 degrees C) until the skin is charred and blistered, about 20-25 minutes. You will know it is ready when it has a lovely smoky aroma and a soft texture. Be careful not to over-roast it, as burnt pepper can taste bitter.
In a large pot, bring salted water to a boil and cook the whole wheat penne rigate until it is al dente, about 8-10 minutes, checking halfway. You want it to feel hearty but not mushy since it will soften a bit more when combined with the dressing. Drain and set aside.
In a bowl, whisk together the balsamic vinegar and extra virgin olive oil until nicely blended. The mixture should smell rich and tangy. This dressing brings everything together, so ensure it is well mixed.
Stir in the finely chopped garlic, salt, and pepper into the dressing. Let the flavors mingle for a minute or two. You should smell the garlic coming through, which adds a fragrant touch.
In a large bowl, toss together the cooked pasta, roasted bell pepper (chopped after cooling), diced tomatoes, black olives, chopped mozzarella, and parsley. Look for a beautiful medley of colors and textures. Mix gently to keep the mozzarella intact.
Pour the dressing over the pasta salad and give it a gentle toss to coat all the ingredients evenly. It should glisten with the dressing. If it looks dry, add a little extra olive oil.
Sprinkle freshly grated Parmesan over the top and give it one last light toss. Be cautious not to overload it with cheese, as too much can overwhelm the other flavors.
Cover the salad and place it in the fridge for about 30 minutes before serving. This helps all the flavors meld together beautifully. Serve chilled for the best taste.