01 -
Turn your oven to 425°F to preheat. You can use parchment paper to line a large, rimmed baking sheet for simpler cleanup later if you'd like.
02 -
Mix the cauliflower with 2 tablespoons olive oil right on the baking sheet, ensuring every piece is lightly coated. Spread it across the tray in a single layer and sprinkle with a bit of salt. Bake 25–35 minutes, tossing halfway to ensure even browning. The florets should be soft with some caramelized edges.
03 -
As the cauliflower finishes roasting, heat 1 tablespoon olive oil in a Dutch oven or soup pot over medium heat until shimmering. Toss in the onion and around ¼ teaspoon salt. Cook, stirring every few minutes, until the onion softens and looks translucent (5 to 7 minutes).
04 -
Stir in the garlic and let it cook for roughly 30 seconds, stirring constantly so it doesn’t burn, just until you smell it. Pour in the broth. Save four of the nicest roasted cauliflower florets for later decoration, then add the rest straight into the pot.
05 -
Turn the heat up to bring your soup mixture to a gentle boil, then lower it to keep a slower simmer. Stir occasionally and let it cook for around 20 minutes so the flavors deepen.
06 -
Take the pot off the heat and let it cool slightly. Little by little, pour the hot soup into a blender (don’t go beyond the max line—it’ll spill!). Add the butter and blend until it’s silky. Drop in the nutmeg and lemon juice, then blend once more.
07 -
Taste and season as needed! Add some extra salt (¼ to ¾ teaspoon based on your broth) and squeeze a tad more lemon if it’s missing a zing. Blend briefly to mix.
08 -
Scoop the soup into bowls, garnish each with one reserved cauliflower floret, and sprinkle over chopped parsley, chives, or green onion. Serve right away while it’s hot.