Line a baking sheet with parchment paper or use a cast iron skillet.
Combine lemon juice, garlic, and sea salt in a small bowl.
Cut through the center of a head of cauliflower, lengthwise, into 3/4-inch to 1-inch thick slices. Cut remaining cauliflower into 1-inch-thick pieces and scatter around cauliflower steaks.
Arrange on the prepared baking sheet or pan in a single layer.
Roast the cauliflower until browned and the stems feel tender when pierced with a knife, 25 to 35 minutes
