Preheat oven to 200 C. Brush a baking tray with a little of the olive oil.
Place the field mushrooms gill side up on the tray and place the other vegetables evenly around.
Strip the thyme sprigs over the vegetables, season and drizzle with the remaining olive oil before roasting in the oven for 25 minutes until caramelized.
While the vegies are roasting, bring the milk to a simmer in a large heavy-based saucepan.
Combine the polenta, buckwheat flour and salt.
Remove the saucepan from the heat and slowly pour the polenta mix into the hot milk while whisking. Place back on a low heat with a simmer pad and cook for 20 minutes, stirring regularly with a wooden spoon to prevent burning.
Stir through the unsalted butter and 50 g Parmesan.
Thickly slice the field mushrooms and toss through the vegetables.
Serve the soft polenta topped with the vegetables and evenly garnish with the blue cheese, pine nuts, extra grated parmesan and freshly cracked black pepper.