Clean the grill grates thoroughly and lightly oil them to ensure the yellow squash doesn't stick. Rub a folded paper towel dipped in cooking oil across the grates. Preheat the grill to medium-high (375-400°F/190-205℃). If using a charcoal grill, make sure the coals are evenly lit and glowing.
Wash your summer squash in cold running water, then pat dry with paper towels or a clean kitchen towel. Place the squash on a cutting board and trim off the ends. Cut the squash into quarters or the desired shape. Aim for slices that are approximately ½-inch thick to ensure even cooking. Arrange the yellow squash slices on a large plate, baking tray, or shallow plate.
Whisk the olive oil, salt, black pepper, minced garlic, chopped basil, dried oregano, and lemon juice in a small bowl. This flavorful marinade will infuse the yellow squash with delightful aromas and enhance its natural taste.
Brush both sides of the yellow squash slices with the marinade, ensuring they are thoroughly coated. Place the slices on the preheated grill grates and cook for approximately 3-4 minutes per side. Keep a close eye on the grill to prevent overcooking or charring. The yellow squash should be tender and display beautiful grill marks.
Remove the grilled yellow squash from the heat and serve immediately. For an extra touch, garnish with chopped basil and grated Parmesan cheese on top. The cheese will melt slightly, adding a delicious finishing touch.