Porcini Mushroom Paste or Powder?

[RebelWithoutaCause]

Waitrose are advertising a new recipe from their 'Beautifully Simple Range' called 'Creamy Bucatini with Mushrooms' , I really want to try it but my small local Waitrose had run out of the Porcini Powder specified in the recipe - I'm wondering if I can substitute some Porcini Mushroom Paste (with Truffle flavour oil) that I already have in my cupboard? All advice welcome. Also, will substituting ordinary spaghetti for Bucatini pasta be ok, or is that a substitution too far ?? !!

We made this last week. It was tasty but a bit bland. I’d say both those substitutions will work but advise you to up the quantities on all the flavourful ingredients (wine garlic porcini paste/powder) as otherwise the crime fraiche drowns then out. Plus lots of seasoning.

Porchini paste sounds like a good substitute though I’ve never personally tried it. Is it similar to porchini stock cubes? They really turbo charge the flavour in any mushroom dish.