Preheat the oven to 180°C/ fan 160°C/ gas mark 4.
In a large bowl, toss the butternut squash, parsnips, sweet potatoes, carrots and fennel with 1 tablespoons olive oil and ½ tsp coarse salt.
Spread in a single layer on a large baking sheet and roast at 180 c until tender and browned in places, about 35 minutes, turning a couple of times while roasting.
While the veggies are roasting, prepare the base of the soup. To a large saucepan over low heat, add 2 tbsp olive oil. Add the onion along with a pinch of salt and a bit of pepper, then sweat, stirring occasionally, until soft.
Stir in the Mevalia bread mix and cook for 3 minutes, stir in the vegetable stock and add the celeriac and thyme. Bring to a boil over medium heat, then reduce heat to gentle simmer uncovered for 15 minutes or until the celeriac is soft. Remove from heat. Pick out the thyme stems and discard.
Next stir in the roasted vegetables then carefully transfer about 1/2 of the chowder to a stick blender, puree until smooth. Return the pureed mixture to the pot and stir to combine. The soup should be thick, rich and creamy.
Add the Mevalia Lattis/ProZero and bring back to the boil.
Finally check seasoning and consistency, when serving garnish with freshly chopped chives.
Serve with warm Mevalia breads.