As we continue our Memorial Day series, we focus on the vibrant, nutritious, and often underappreciated stars of the grilling world - vegetables. Grilling can transform the humblest of vegetables into smoky, caramelized delights that add color, variety, and healthful balance to your barbecue spread. We will guide you through a classic recipe for Grilled Vegetable Skewers and a gourmet twist with Balsamic Grilled Portobello Mushrooms.

Grilled Vegetable Skewers

Ingredients:

1. 2 bell peppers (any color), cut into chunks
2. 1 zucchini, sliced into thick rounds
3. 1 red onion, cut into chunks
4. 1 cup of cherry tomatoes
5. Olive oil
6. Salt and pepper to taste
7. Wooden or metal skewers

Instructions:

1. If using wooden skewers, soak them in water for at least 20 minutes before grilling to prevent burning.
2. Preheat your grill to medium heat.
3. Thread the vegetables onto the skewers. Drizzle with olive oil and season with salt and pepper.
4. Grill the skewers for about 10-15 minutes, turning occasionally, until the vegetables are tender and slightly charred.

Balsamic Grilled Portobello Mushrooms

Ingredients:

1. 4 large Portobello mushrooms, stems removed
2. 1/4 cup of balsamic vinegar
3. 2 tablespoons of olive oil
4. 2 cloves of garlic, minced
5. Salt and pepper to taste

Instructions:

1. In a small bowl, whisk together balsamic vinegar, olive oil, garlic, salt, and pepper.
2. Place the mushrooms in a dish and pour the marinade over them. Let them marinate for about 15-30 minutes, turning occasionally.
3. Preheat your grill to medium heat.
4. Grill the mushrooms for about 5-7 minutes per side, until tender and slightly charred.

Grilling Tips for Vegetables:

1. Prep and Pre-Cook When Needed: Some vegetables like corn, potatoes, or beets may benefit from being partially cooked before grilling. 
2. Seasoning Is Key: Don't be shy about seasoning your vegetables before grilling. At the very least, use olive oil, salt, and pepper. Other options include herbs, spices, or marinades.
3. Size Matters: Cut vegetables into sizes that will cook evenly and are less likely to fall through the grill grates. For smaller vegetables, consider using a grill basket or skewers.

With these delectable recipes and tips, your Memorial Day menu can celebrate vegetables in all their charred, smoky glory. Grilling vegetables enhances their natural sweetness and adds a hint of smokiness, creating a tasty and healthy addition to your Memorial Day feast. Enjoy the grilling journey!