Balsamic Roasted Portbello Mushroom Veggie Sandwich

Ingredients (12)

• 1/4 cup olive oil
• 1/4 cup balsamic vinegar
• 1 teaspoon Dijon mustard
• 1 teaspoon minced garlic
• 1/2 teaspoon Kosher salt
• pinch ground pepper
• 1/2 yellow onion, sliced in rings
• 2 small or 1 large zucchini, sliced in sticks
• 4 portobello mushrooms, sliced
• 12 slices whole grain seedy bread
• 4 slices Muenster cheese
• 1 container La Terra Fina Parmesan Artichoke spread