Heat the olive oil in a large stock pot or Dutch oven over medium heat. Sauté the diced onion for about 5 minutes until it becomes translucent and fragrant.

Add the minced garlic and red chili flakes to the pot. Continue cooking for another minute, stirring frequently.

Combine the potatoes, broccoli, vegetable stock, salt, and black pepper in the pot. Stir together, then bring to a boil. Lower the heat, cover, and let it simmer for 25 minutes.

Blend the soup using a hand blender until creamy while retaining some chunky pieces for texture.

Bring the soup back to a gentle boil, then add the ditalini pasta. Cook for 10-12 minutes until al dente.

Stir in the crumbled feta and chopped parsley, allowing the feta to melt slightly into the soup.

Serve the soup hot, topped with extra crumbled feta and a sprinkle of red chili flakes if desired.