Start by washing your seasonal vegetables thoroughly. Cut the red bell pepper, zucchini, yellow squash, and red onion into 1-inch pieces.

In a large mixing bowl, combine the diced vegetables. Pour in the olive oil, and generously sprinkle with salt and pepper. Toss the mixture until well-coated.

Soak wooden skewers in water for 30 minutes to prevent burning. Alternate threading the colored vegetables onto each skewer in a visually appealing pattern.

Preheat your grill to medium-high heat, about 350°F to 400°F (175°C to 200°C).

Once the grill is ready, place the skewers directly over the heat. Grill the vegetable skewers for 10–12 minutes, turning occasionally to ensure even cooking.

After grilling, remove the skewers from the grill and allow them to cool slightly before serving.