Portobello Red Pepper Pita

Name: Portobello Red Pepper Pita
Ingredients: 4 large portobello mushrooms ; stems removed (or 8 to 10 oz white or crimini mushrooms, sliced); 1/2 large red onion ; thinly sliced; 2 whole wheat pitas; 2 cups arugula; 1 medium red pepper from a jar ; cut into 1/2 inch slices (or you can slice up a fresh red pepper and roast it with the other veggies); 4 tbsp Tahini Date sauce:; 3/4 cup raw tahini; 1/2 cup water; 1 tbsp fresh lemon juice; 1 medjool date ; pitted and chopped; 1 clove garlic; 1 tbsp no salt seasoning; 1 tsp Bragg Liquid Aminos or low-sodium soy sauce