Remove the eyes and beak of the octopus
Rinse the octopus in cold salted water
Bring a large pot of water to a simmer and add the onion, lemon, garlic, bay leaves, peppercorns, salt, and thyme
Dip the octopus tentacles in the simmering water 2-3 times to help curl them up
Bring the water to a boil, then reduce to a simmer, cover and cook for at least 45 minutes
Check the octopus for doneness by pressing a thin knife into the thickest part of the tentacle
Remove the octopus from the water and let it cool for 30 minutes
In a large bowl, mix together the olive oil, oregano, thyme, lemon zest, garlic, salt, and pepper
Add the cooked octopus tentacles to the marinade, stir to coat, and refrigerate for at least 4 hours or overnight
Bring the marinated octopus to room temperature, then grill the tentacles for 2-3 minutes per side
Serve the grilled octopus with a salad and lemon wedges
