Preheat the oven to 375°F (190°C). Spread the cremini and oyster mushrooms on a baking sheet and drizzle with olive oil.

Roast the mushrooms for 18–20 minutes, flipping the pieces around once halfway through, until lightly browned and tender. Set aside.

Warm olive oil in a large pot over medium heat for 90 seconds. After 90 seconds, when the oil is hot, add the onion and sauté for 6 minutes, stirring occasionally, until lightly golden and softened.

Add the whole garlic cloves, celery, sage, mustard, thyme, coriander, paprika, black pepper, and bay leaves and cook for 4–5 minutes to soften the celery and garlic.

Add half of the roasted mushrooms, the dried porcini mushrooms, cannellini beans, and stock. Bring to a boil over high heat, then reduce to low heat and simmer uncovered for 20 minutes.

Remove the bay leaves. Transfer the soup in batches to a blender and blend until smooth, or use an immersion blender in the pot.

Return to low heat, stir in the rest of the roasted mushrooms, parsley, and tamari.

Serve hot, garnished with parsley leaves, a drizzle of olive oil, and coarsely crushed black peppercorns.