Wash, halve, and remove the pith and stalk from the red pepper.
Smear the red pepper with olive oil and roast for 40 minutes.
Dice the mushrooms and lay on a parchment paper on a baking tray. Drizzle with a Tbsp of oil and a Tbsp soy sauce over the mushrooms and put the tray in the oven with the red pepper. The mushrooms will take just 15 minutes, so take them out before the red pepper and set aside.
Dice the red pepper into 5x5mm pieces and set aside.
Peel and dice the potatoes and cut into 5x5mm pieces.
Simmer the potato in water until tender. Drain and set aside.
Cook the corn cobs over a grill until starting to char. Ideally use charcoal as it adds a great smoky flavour. Alternatively, use the broiler.
Allow to cool a little.
Sauté the diced onion in 30 g butter until starting to brown.
Add the diced garlic and sauté until you get the wonderful garlic fragrance (a couple of minutes).
Add the flour and stir into the butter and onion. Keep stirring until it becomes a light brown colour.
Slowly pour in the dashi and vegetable stock (or chicken stock).
Cut the kernels off the corn cobs.
Add half the corn kernels and half the potato to the soup, together with the miso and soy sauce.
Blend with an immersion blender until smooth. Alternatively, use a normal blender.
Strain to remove any remaining solid bits.
Add the remaining potato and corn, the diced roasted red pepper, mushrooms, and the diced green chilli. Keep a few mushrooms and chilli slices for a garnish.