Indoor Grilled Summer Veggie Sandwich

For balsamic vinegar marinade

1. Mix all the ingredients for the marinade in a small bowl and set aside.

For King oyster mushroom

1. Preheat oven to 400 degrees.
2. Line the baking sheet with parchment paper.
3. Lay the mushroom and brush with melted vegan butter.
4. Sprinkle some salt.
5. Bake for 10 minutes.
6. Broil for 5 minutes and set aside.

For red onion

1. Heat the cast iron pan with grill marks with 1/2 tablespoon of grapeseed oil.
2. Once the pan is heated (4-7minutes), place the onion on the pan and cook for 3-4 minutes on each side. Do NOT move the onion around. It won’t develop the grill marks if you move it around.
3. When onions are cooked, move them out of the pan and set them aside.

For eggplant

1. Keep your oven to 400 degrees Fahrenheit.
2. Line a baking sheet with parchment paper and keep it close to the cast iron pan.
3. Add the cut eggplants with 2-3 tablespoons of balsamic vinegar marinade in a large bowl and toss to coat.
4. On the same cast iron pan, place the eggplant and cook for 3-4 minutes. Do not move the eggplant once you place them on the pan. Otherwise, it won’t develop the grill marks. 
5. Flip the eggplants and continue to cook for additional 2-3 minutes. 
6. Transfer the eggplants to the baking sheet and brush the eggplants with balsamic marinade. Sprinkle some salt over.
7. Place them in the oven and cook for 5 minutes. 
8. Take them out of the oven and set them aside.

For zucchini and yellow squash

1. Keep your oven to 400 degrees Fahrenheit.
2. Line a baking sheet with parchment paper and keep it close to the cast iron pan.
3. Add the cut zucchini and yellow squash with 2-3 tablespoons of balsamic vinegar marinade in a large bowl and toss to coat.
4. On the same cast iron pan, add the remaining 1/2 tablespoon of grapeseed oil.
5. Place the vegetable on the pan and cook for 3-4 minutes. Do not move the vegetable once you place them on the pan. Otherwise, it won’t develop the grill marks. 
6. Flip the vegetable and continue to cook for additional 2-3 minutes. 
7. Transfer the vegetable to the baking sheet and brush them with balsamic marinade. Sprinkle some salt over.
8. Place them in the oven and cook for 5 minutes. 
9. Take them out of the oven and set them aside.

For mini sweet pepper

1. Add the peppers with 1-2 tablespoons of balsamic vinegar marinade in a large bowl and toss to coat.
2. On the same cast iron pan, place the pepper and cook for 2-3minutes. 
3. Flip the peppers and continue to cook for additional 2 minutes. 
4. Take it out of the pan and set it aside.

For sandwich

1. Cut the focaccia bread horizontally with a bread knife. 
2. Smear about 1-2 tablespoons of pesto of your choice on both sides of the bread. 
3. Layer the grilled vegetables on top of the bottom part of the bread.
4. Top it off with the focaccia bread and cut it into a little slider size. Secure with a toothpick so the vegetables won’t slide off of the sandwich.