01 -
Preheat oven to 375 degrees F.
02 -
Use a melon baller to scoop out top center of onion about 1/3 way down to create a well. Place on aluminum foil and add butter to well. Mix seasonings with olive oil and pour over butter, letting mixture drip down sides. Season with salt.
03 -
Seal onion tightly in aluminum foil and place in small baking dish or cast iron skillet to catch any seeping oil.
04 -
Cook on center rack for 1 hour. Check that onion is fork tender, center jiggles, and slightly caramelized. If needed, reseal and cook additional 10 minutes.
05 -
For extra caramelization, open foil, add more melted butter/oil and pinch of salt. Broil 5-10 minutes until golden brown on top, watching carefully.
06 -
Remove outer layer, season additional layers with salt if desired. Pour accumulated juices over top. Serve hot with rice, chickpeas or roasted vegetables.