Position a rack in the top of the oven and preheat it to 400F. Line a sheet pan with parchment paper.
Set a large pot over medium heat and add 3 tablespoons olive oil. Add the garlic and let it sizzle for a minute or so. Add the cauliflower and cook, stirring occasionally, until the cauliflower is fully soft, 7 to 9 minutes. Season with a large pinch of salt, a few cracks of black pepper, and the pepper flakes.
Transfer the cauliflower and garlic to a blender. Add ½ cup of Parmesan to the blender along with the lemon, brine, and 1 cup of the vegetable broth. Blend until very smooth (this takes me 2 to 3 minutes of blending). Taste and season, as preferred, but I find the cheese and lemon get it plenty salty.
In the same pot, bring the remaining 3 cups of vegetable broth to a boil and add the orzo. Boil until most of the broth has been absorbed into the orzo, 6 to 8 minutes. Pour in the cauliflower cream, turn off the heat, and
stir to combine. If needed to keep everything smooth, add a few splashes of hot water.
Grate the remaining Parmesan and spread it into four large rounds on the lined sheet pan, making each round the same size as the shoulder of the dishes you plan to serve the orzo in. Bake until you have lightly golden and crisp fricos, 6 to 7 minutes.
To serve, portion the orzo into four bowls. Gently place the frico on top and use a spoon to, well, shatter!