Preheat the oven to 350°F.
In a medium pot over medium-high heat, lightly boil the broccoli for 2 to 3 minutes, or until almost fork-tender.
Drain well, transfer to a food processor or blender, and pulse until roughly chopped.
Transfer to a large bowl, and add the artichoke hearts, eggs, onion, almond milk, almond flour, and garlic powder.
Season with salt and pepper, and stir well.
Grease an 8-inch round baking pan with the butter, and transfer the mixture to it.
Bake for 40 to 45 minutes, or until no longer runny, and serve.