In a large pot, combine water, halved onion, smashed garlic, black peppercorns, kosher salt, lemon juice, parsley stems, and bay leaves. Bring to a boil. Gently add the baby octopus, reduce heat to medium-low, and simmer for about 1 hour.

Carefully drain the braised octopus using a fine mesh strainer. Discard solids but save the braising liquid if desired. Transfer warm octopus to a bowl to cool slightly.

In a bowl, whisk together extra virgin olive oil, minced garlic, and dried red chili flakes. Pour marinade over warm baby octopus and coat well. Cover with plastic wrap and refrigerate for at least 12 hours, ideally up to 24 hours.

Preheat a skillet or BBQ grill over medium-high heat. Add canola oil and heat until shimmering. Add the marinated octopus to the hot pan, searing for about 3-5 minutes on each side until crispy and golden.

Arrange octopus on a platter, garnish with sliced red chili, and drizzle with fresh lemon juice. Serve with lemon wedges and crusty bread.