One thing I love about Yucatecan food is the achiote seasoning paste (recado rojo), which is, among other things the basis of the marinade used in the famous pibil dishes.
Achiote paste is made from the hard, red seeds of a native tree.
You can buy birth the whole seeds and pre-ground achiote from on-line suppliers and specialist shops (like Lupe Pintos). It's often sold as "annatto", which is the Brazilian name for it.
These same shops and suppliers usually sell a pre-made recado rojo (El Yucateco is a good brand), in case you wanna save yourself some work.
But being MexiGeek, I actually enjoy doing it the hard way, which is grind it yourself in a molcajete (mortar and pestle).
However, I do but pre-ground achiote, because those seeds are so hard even a spice-grinder needs a few minutes to cope.
(And you can, of course, do the whole thing in a food processor.)
There is no one set recipe, but there are a few essential ingredients plus a few likely "extras". And there is a typical ratio of amounts to get the flavour balance right.
The essentials are:
1 tbsp achiote
1 tsp Mexican oregano
1 tsp black peppercorns
1 tsp allspice berries
1 tsp cinnamon (canela)
1/2 tsp cumin
5 cloves garlic
1-2 tbsp cider vinegar
You can also embellish this with:
1/2 tsp cloves
1/2 tsp coriander seeds
You may also need to add an extra tablespoon or two of plain flour at the end if the paste is too loose.
Keeping in mind that I use pre-ground achiote, I'm writing this in "grinding order".
(If you're using while achiote seeds, grind them separately in a spice-grinder.)
Peel the garlic and grind it down to a paste in your molcajete.
Crumble a one-inch stick of (preferably) Mexican cinnamon into the molcajete and grind it down.
(In Mexico they use canela or "true cinnamon", as opposed to the cassia bark we use in Europe.)
Add the allspice (and clove, if using) and continue grinding.
(The cinnamon won't break down completely until the end.)
Add the peppercorns and continue grinding. When they have broken down add the cumin.
Add the coriander seeds (if using) once the cumin has broken down; add the oregano and "mix" it in with the pestle.
Now add the achiote and grind it in until it looks well incorporated.
Now add the vinegar a little at a time and continue "mixing" with the pestle. If the paste is too loose, add some flour.
You should let this paste stand in the fridge overnight if you want it to really rock.
Then you can make cochinita pibil!