Baked Feta with Roasted Red Peppers and Lemon–Oregano Broth

Name: Baked Feta with Roasted Red Peppers and Lemon–Oregano Broth
Ingredients: 2 sprigs fresh oregano; 1 rib celery, cut into 1 pieces; 1 medium carrot, cut into 1 pieces; 1 small white onion, cut into 1 pieces; 1 tsp. freshly grated lemon zest; Salt; 1 red bell pepper, roasted, peeled, and cored, cut into 1⁄3 squares; 3 tbsp. plus 1 tsp. olive oil, preferably Greek; Salt and freshly ground black pepper; 6 small wedges pita bread; 6 (1 1⁄2) cubes feta, preferably Dodoni; 2 tbsp. microgreens (optional)