Preheat your oven to 400 degrees Fahrenheit.
Chop the zucchini, red bell pepper, and red onion into bite-sized pieces.
Toss the chopped vegetables with half of the olive oil and a pinch of salt and pepper on a baking sheet.
Roast the vegetables for 20 minutes or until they are tender and slightly browned.
While the vegetables roast, bring a pot of salted water to a boil and cook the whole wheat penne according to the package instructions.
Season the chicken breast with salt, pepper, and a dash of dried oregano.
Grill the chicken over medium-high heat for about 6 to 7 minutes per side until the internal temperature reaches 165 degrees Fahrenheit.
Let the chicken rest for 5 minutes before slicing it into thin strips.
In a large mixing bowl, whisk together the remaining olive oil and the fresh lemon juice to create the dressing.
Add the cooked pasta, roasted vegetables, and sliced chicken to the bowl and toss thoroughly.
Gently fold in the fresh baby spinach so it wilts slightly from the residual heat of the pasta and vegetables.
Serve immediately while warm or refrigerate to enjoy as a cold pasta salad.