Cook the shallot in 1 tbsp butter until softened and translucent
Add the mushrooms, garlic, mushroom powder and thyme. Season and cook for 10 minutes
Deglaze with the sherry and soy, then simmer until the mixture is almost dry
Remove the thyme, then blend with the cream and milk
Blend in the 50g melted butter, aquafaba and cornflour slurry, then season
Scrape into a small baking dish set in a larger dish full of water and cover with foil
Bake at 140°C fan for 25 minutes. Leave to cool
Transfer to a bowl and whisk until light. Chill until needed
Mix together crumb ingredients, season, then spread onto a lined tray and bake for 12 minutes at 160°C fan. Leave to cool
Blanch the tarragon for 10 seconds, then refresh in ice water. Pat dry and blend with the oil for 2 minutes or until bright green. Strain through a cheesecloth-lined sieve
Brush the bread with oil and grill until deeply golden
Rub the warm toasts with garlic, then cut into even pieces
Transfer parfait to a piping bag and pipe over the toasts. Scatter over the crumb and finish with tarragon, chilli, salt and tarragon oil
