When I have come across this in american recipes I tend to use a mix of 1 part dried oregano, 1 part dried basil and about 2 3rds a part dried thyme and it has worked if that helps.
Looking at this recipe though I would be really tempted to substitute some or all of that heavy cream for mozzarella cos the flavours look good but with heavy cream its gonna be really dense.
Edit: Actually would be extra important if it calls for cooking the gnocci in the sauce as the gnocci is gonna release a load of starch in the sauce.
When I have come across this in american recipes I tend to use a mix of 1 part dried oregano, 1 part dried basil and about 2 3rds a part dried thyme and it has worked if that helps.
Looking at this recipe though I would be really tempted to substitute some or all of that heavy cream for mozzarella cos the flavours look good but with heavy cream its gonna be really dense.
Edit: Actually would be extra important if it calls for cooking the gnocci in the sauce as the gnocci is gonna release a load of starch in the sauce.