Tofu Mushroom and Veggie Pita Grilled Sandwich

1 lb. pkg. tofu (extra-firm)
1 - 2 cup balsamic vinegar
1/4 - 1/2 cup olive oil (usually less needed)
1 tablespoon (each) basil, oregano, thyme (or 3 tablespoons Italian seasoning with these herbs included)
salt & pepper, to taste
2-3 clovers garlic
3-5 sliced portabello mushrooms (1/2 inch thick slices, lengthwise)
1 bell pepper, sliced in long 1/2 inch thick slices (green, red or yellow work great)
1/4 cup orange juice (optional for marinade)
1 teaspoon lemon juice (optional for marinade)
1 package pita bread (sliced in half)
6 - 8 slices vegan mozzarella (optional)
4 tablespoon vegan mayonnaise (Vegenaise or Nayonaise) optional
3 tablespoon Dijon mustard (optional)