Brush both sides of cauliflower steaks with grape seed or avocado oil. Toss leaves with 1 teaspoon of oil. In small bowl, mix salt with garlic powder, paprika and ginger; toss leaves with ¼ teaspoon. Sprinkle remaining salt mixture evenly over both sides of cauliflower steaks.
Place cauliflower on a baking sheet. Cover tightly with foil. Roast 10 minutes.
Remove from oven and remove foil. Sprinkle leaves on roasting pan. Reduce oven temperature to 450F.
Return pan to lower rack of oven. Roast 6 minutes.
Transfer roasted leaves to a plate.
Turn steaks and continue roasting until golden brown and tender.
Transfer steaks to serving plates. Meanwhile, prepare desired sauce.
Thai Coconut Pepper & Onion Sauce. Heat skillet over medium-high heat. Add oil and heat until shimmering. Add peppers and onions, cook, stirring, until onions soften and peppers are crisp tender. Reduce heat to low. Add sauce; simmer for 1 minute. Spoon sauce over cauliflower steaks. Top with roasted cauliflower leaves. Garnish with lime wedge.
Korean BBQ Mushroom Sauce. Heat oil in skillet over medium-high heat until shimmering. Add mushrooms; cook, stirring, 3 to 4 minutes or until mushrooms release their liquid and brown. Reduce heat to low. Add sauce, stirring to coat mushrooms. Simmer for 1 minute. Spoon over cauliflower steaks. Sprinkle with sesame seeds and cilantro.
Lemongrass Basil Shitake Sauce. Heat oil in skillet over medium-high heat until shimmering. Add mushrooms; cook, stirring, 3 to 4 minutes or until mushrooms release their liquid and brown. Reduce heat to low. Add sauce, stirring to coat mushrooms. Simmer for 1 minute. Spoon over cauliflower steaks. Sprinkle with green onions.