Prepare the ingredients:
Heat the oven to 350°F. Cut four 12-inch square sheets of aluminum foil. Arrange garlic bulbs on one sheet of foil and drizzle with 1 Tbs. of the olive oil. Fold and crimp the foil into a pouch around the garlic. Fold up the shallots, lemongrass and galangal or ginger the same way in their own foil pouches, using the remaining 3 Tbs. of olive oil. Roast the aromatics until soft and fragrant: 60 minutes for the garlic, 35 to 40 minutes for the shallots, 25 minutes for the lemongrass and 20 minutes for the galangal. Remove from the oven and let cool. When the pouches are cool enough to handle, unwrap and mince each ingredient, and transfer them to separate bowls.
Put the Anaheim and de arbol chiles in a large bowl, and add enough hot water to cover, plus a pinch of sea salt. Let the chiles soak for 30 minutes. If you prefer a less-spicy curry, remove the ribs and seeds from most or all of the chiles (leave them in for a spicy dish), and then mince the chiles.
In a small, dry skillet, toast the peppercorns, coriander, cardamom, cumin, caraway and cloves separately over medium-low heat until each spice is fragrant, about 15 seconds. Cool and then grind each spice separately in a coffee or spice grinder.
Prepared curry paste can be refrigerated in a sealed container for up to a month.