In a heavy pot or Dutch oven, heat 2 tablespoons Salute Santé! Grapeseed oil over medium-low. Add the onion and cook, stirring occasionally, until tender and translucent, 6 to 8 minutes. Add the garlic and cook until fragrant, about 30 seconds. (Be careful not to let the garlic scorch!)

Add the stock, cauliflower, salt and pepper, and bring to a boil over high. Lower the heat, cover, and simmer until the cauliflower is tender when pierced with a fork, about 10 minutes.

Working in batches, carefully transfer the vegetables, stock and ¼ cup rosemary oil to a blender and blend on high until creamy. Add more rosemary oil to taste, and blend to combine. Return the soup to the pot and bring to a simmer. If the soup seems thin, let it simmer for 5 to 10 minutes to reduce slightly. (Remember: The soup will continue to thicken as it cools.) Season to taste with salt and pepper.

Serve hot. Garnish each serving with a swirl of lemon oil, a few croutons, and a sprinkle of lemon zest. The soup will thicken as it sits; add more stock as necessary when reheating.

In a skillet, heat the Salute Santé! Rosemary oil over medium. Add the bread cubes, sprinkle generously with salt and pepper, and cook, tossing often, until toasted all over, 4 to 5 minutes. Transfer the croutons to a plate or board to cool.