Spinach, Red Pepper and Feta Frittata

INGREDIENTS

• 10 eggs
• Kosher salt and freshly ground pepper, to taste
• 2 tsp. chopped fresh oregano, plus more for garnish
• 1/2 cup crumbled feta cheese, plus more for garnish
• 2 Tbs. plus 1 tsp. olive oil
• 1 large red bell pepper, cored, seeded and sliced into 1/4-inch strips
• 1 1/2 cups firmly packed baby spinach