Which recipe are you following? If you're preparing duxelles, I don't think a lot of harm [apart from wrecking the flavour] would come from leaving out the dried mushrooms and not adding anything in as a substitute.
I don't think I'd be averse to sweet red peppers instead of fresh mushrooms if you think the water content needs to balance.
BBC good food one, I used lentils instead of mushrooms, and also wilted spinach with boiling water. Just finished cooking the first half of tenderloin. Looks ok, might taste rank!
Which recipe are you following? If you're preparing duxelles, I don't think a lot of harm [apart from wrecking the flavour] would come from leaving out the dried mushrooms and not adding anything in as a substitute.
I don't think I'd be averse to sweet red peppers instead of fresh mushrooms if you think the water content needs to balance.