Preheat the oven to 350 ℉ (180 ℃) with convection (fan).
Cut the cauliflower florets and toss them in 2 tablespoons of olive oil, salt and pepper. Cut off the top of the garlic bulb, place it on aluminum foil, drizzle with olive oil, and wrap in the foil.
Place the cauliflower florets and garlic on a baking tray and into the oven. Roast for 20-25 minutes until golden and tender.
Chop the onion and peel and dice the potatoes.
Add olive oil to a pot and sauté the onion until tender and translucent.
Add the potatoes, roasted cauliflower and squeeze the roasted garlic into the pot. Then, add the vegetable broth and bring everything to a simmer. Let it cook for 10-15 minutes until the potatoes are soft.
Once the potatoes are soft, blend the soup with a (hand-held) blender until it is smooth. Add the cream and cheddar cheese and mix until they melt. Done! Taste for salt and pepper and adjust if needed.
