We tend to use basil as a garnish that is minty, zesty, peppery and with some intense clove like notes. Refreshing and intense in flavor a little goes a long way. Oregano is more often cooked with a dish to develop the flavor and it is earthy, herbaceous, woody and pungent with mint to citrus notes.
In appearance caraway seed and fennel seed seem quite similar, elongated with ridges running lengthways from one end to the other. Both seeds belong to the same plant family and share an anise or licorice flavor. Caraway also has notes of nuttiness and an earthy sort of muskiness added that is missing from fennel
Cajun seasoning is made from salt, paprika, garlic, black and white pepper, onion powder, ground cumin, cayenne pepper and then oregano, thyme and any other suitable herbs you like to add. You can mix the paprika to use smoked, sweet or hot.
Gremolata is a traditional Italian ‘sauce’ with parsley, garlic and lemon zest. No other ingredients are required and you can see that this means it is more of a garnish than a sauce. It has evolved to include a little bit of lemon juice and even olive oil, however this moves into more of a pesto.
A good fajita seasoning will allow the smokiness of that history to come through alongside a fiery heat, smoked paprika and chili work best. It is important to let the fresh ingredients of the fajita come through as well, so a few background spices like cumin, garlic and coriander allow that.
Parsley is a useful biennial that will grow outdoors in colder climates and basil being a tender annual. Both can be used in cooking with slightly different taste profiles and history of culinary uses. Nutritionally both of these herbs are loaded with vitamins and minerals as well.