Follow these simple, step-by-step instructions to bring this delicious and colorful pasta dish to life. The key is to multitask by preparing the vegetables while the pasta is cooking, ensuring everything comes together in under 30 minutes.

1. Cook the Pasta:
Begin by bringing a large pot of heavily salted water to a rolling boil. Think “salty like the sea” – this is your only chance to season the pasta itself. Add the penne and cook according to the package directions until it is al dente. This means it should still have a slight, firm bite to it. Overcooked pasta can become mushy and won’t hold the sauce as well. Before draining, carefully scoop out and reserve at least 1 cup of the starchy pasta water. This is a crucial step! Once reserved, drain the pasta in a colander and set it aside.

2. Sauté the Aromatics and Harder Vegetables:
While the pasta is boiling, heat the olive oil in a large skillet or Dutch oven over medium heat. Once the oil shimmers, add the minced garlic and sauté for about 30-60 seconds until it becomes fragrant. Be careful not to let it brown, as this can make it taste bitter. Add the chopped red bell pepper and zucchini to the skillet. Season with a pinch of salt and black pepper. Cook, stirring occasionally, for about 5-7 minutes, until the vegetables are tender-crisp. You want them cooked through but still retaining a bit of a bite.

3. Add the Softer Vegetables:
Next, add the halved cherry tomatoes to the skillet. Continue to cook for another 3-4 minutes, stirring gently. The tomatoes will begin to soften, and their skins will start to blister and wrinkle. As they cook, they will release their sweet juices, which will form the base of a light, delicious pan sauce.

4. Wilt the Spinach:
Turn the heat down to low. Add the large handfuls of baby spinach to the skillet. It may seem like a lot at first, but it will wilt down significantly. Gently stir the spinach into the other vegetables until it has completely wilted, which should only take about 1-2 minutes.

5. Combine Everything:
Add the drained penne pasta directly into the skillet with the cooked vegetables. Pour in the basil pesto and add the grated Parmesan cheese. Now, it’s time for the magic ingredient: the reserved pasta water. Start by adding about 1/2 cup of the pasta water to the skillet.

6. Create the Sauce and Serve:
Using a pair of tongs or a large spoon, toss everything together vigorously. The starchy pasta water will help the pesto and Parmesan melt into a smooth, creamy sauce that beautifully coats every single piece of penne and all the vegetables. If the sauce looks too thick, add more of the reserved pasta water, one tablespoon at a time, until you reach your desired consistency. Taste the pasta and adjust the seasoning with more salt, black pepper, or red pepper flakes if desired. Serve immediately, garnished with an extra sprinkle of freshly grated Parmesan cheese and fresh basil leaves if you have them.