While water comes to a boil for the pasta, mince your garlic cloves finely. In a small bowl, whisk together the olive oil, red wine vinegar, minced garlic, oregano, salt, and black pepper. Let this dressing sit while you cook—the garlic will infuse the oil and vinegar with deeper flavor. Halve your cherry tomatoes lengthwise (they'll be easier to eat this way) and thinly slice the red onion. I like to slice the onion just before mixing to keep it crisp and prevent it from becoming too sharp-tasting.

Bring a large pot of salted water to a rolling boil. Add the penne and cook according to package directions, aiming for al dente texture—the pasta should have a slight firmness when you bite it, not mushy. Drain the pasta in a colander but do not rinse it; the starch on the pasta helps the dressing cling to it better. I always use Barilla because it holds its texture perfectly and doesn't get gummy when dressed.

While the pasta is still warm (but not piping hot), transfer it to a large mixing bowl. Add the fresh spinach, halved cherry tomatoes, sliced red onion, and feta cheese crumbles to the warm pasta. Pour the dressing from Step 1 over everything and toss gently but thoroughly, making sure every component is coated evenly. The warmth of the pasta will slightly soften the spinach and help the flavors meld together beautifully. I prefer using Athenos feta crumbles because they distribute throughout the salad without breaking down.