Preheat oven to 400°F. Cook cauliflower rice in pot of boiling salted water for about 2 minutes or until tender; drain well in fine sieve. Let cool completely.
Transfer cauliflower rice to clean tea towel and squeeze dry; transfer to bowl. Combine ground flaxseed with 3 tbsp water. Stir together cauliflower, gluten-free flour, flaxseed mixture, nutritional yeast, Italian herb seasoning, garlic powder, salt and pepper.
Line 12-inch pizza pan with parchment paper; drizzle with 1 tbsp olive oil. Add cauliflower mixture to center of pan, spreading 1/4-inch thick to form 10-inch round, making edges slightly thicker to form crust. Bake for 25 to 30 minutes or until edges start to turn golden and crust is firm.
Meanwhile, heat remaining oil in skillet set over medium heat; cook Quorn Meatless Strips for 5 to 8 minutes or until heated through. Let cool slightly.
Using 2 forks, shred strips to resemble pulled meat. Toss with barbecue sauce; set aside.
Sprinkle mozzarella over cauliflower crust. Top with pulled “meat,” red onion and corn. Bake for 8 to 10 minutes or until golden brown and cheese melts. Garnish with green onions. Cut into wedges before serving.
Tip: Substitute vegan Parmesan cheese for nutritional yeast if desired.