Step 1: Cook the Spaghetti: Bring a large pot of salted water to a boil. Add the spaghetti and cook according to package directions until al dente. Drain the spaghetti and rinse with cold water to stop the cooking process. This prevents the pasta from becoming mushy and ensures it remains firm and separate.
Step 2: Prepare the Vegetables: While the spaghetti is cooking, prepare the vegetables. Dice the red and green bell peppers into small, uniform pieces. Thinly slice the red onion. Halve the cherry tomatoes. Slice the black olives. Having all the vegetables prepped and ready to go makes the assembly process much smoother.
Step 3: Make the Vinaigrette: In a small bowl, whisk together the olive oil, red wine vinegar, minced garlic, dried oregano, salt, and pepper. Ensure the ingredients are well combined to create a flavorful dressing. Taste and adjust seasonings as needed to achieve the desired balance of acidity and flavor.
Step 4: Assemble the Salad: In a large bowl, combine the cooked spaghetti, diced bell peppers, sliced red onion, halved cherry tomatoes, sliced black olives, cubed mozzarella cheese, chopped fresh basil, and grated Parmesan cheese. Gently toss the ingredients together to distribute them evenly.
Step 5: Dress the Salad: Pour the vinaigrette over the spaghetti and vegetable mixture. Toss gently to coat all the ingredients evenly with the dressing. Avoid over-mixing, which can cause the pasta to break and the vegetables to become bruised.
Step 6: Chill and Serve: Cover the bowl and refrigerate the salad for at least 30 minutes to allow the flavors to meld together. Chilling also helps the salad to stay fresh and prevents it from becoming too warm. Before serving, give the salad another gentle toss. Serve cold and enjoy.
Optional Tips: For a spicier salad, add a pinch of red pepper flakes to the vinaigrette. Grilled chicken or shrimp can be added for extra protein. Different cheeses, such as provolone or feta, can also be substituted for the mozzarella.