Preheat over to 425 degrees
On a baking sheet, toss celeriac, sweet potato & carrots with 2 tbsps olive oil
Spread in a single layer & cover with foil
Roast for 25 minutes
Remove foil, toss vegetables & roast for 20 minutes, uncovered, or until vegetables are tender when pierced with a fork
In a medium pot over medium heat, warm the remaining 1 tbsp oil
Cook onion & garlic, stirring, for 7-10 minutes, or until mixture is tender & translucent
Stir in rosemary, salt, curry powder & pepper & cook for 2-3 minutes
Add roasted vegetables & gently combine
Add the stock
Increase heat to high & bring to a boil
Reduce the heat to medium, add collard greens, cover & simmer for about 10 minutes
Ladle into warm bowls, drizzle with olive oil & spoon slowly to savor every morsel!