Start by seeding and destemming the dried chiles. Put them in a bowl and pour boiling water over them. Set a plate over the bowl to cover and let this sit. Heat up a cast iron or other heavy skillet and, when it’s hot, set the quartered onion and the unpeeled garlic cloves on it to char. Do not oil the pan. Rotate the onion and garlic so it’s nicely charred.
Put the onions, garlic, tomato paste, oregano and the rehydrated chiles, along with a little bit of the soaking water, into the bowl of a blender. Puree, adding enough of the chile soaking water to give the mixture the consistency of barbecue sauce. Add salt, hot sauce and lime juice to taste. This marinade can be made ahead of time, up to a week. It stores well in the fridge.
The day before you want to cook your teal, cut out their backbones with shears. I like to pull out the ribs, too. Rinse them well and set the birds, breast side up, on a cutting board. Use the palm of your hand to flatten them a bit more.
Massage the marinade into the teal, and use a little more than you think you need. Set them, breast side down, in a covered container that will just about hold them all. Refrigerate for a day or even two. Now yes, you can marinate the teal for less time, but they won’t be as good.
When you are ready to grill your teal, take the container out and let the birds come to room temperature for 30 minutes or so. Start a hot fire on your grill. Charcoal and wood are my preference, but it works fine with gas, too.
Make sure your grates are clean. Set the ducks, breast side up, over the coals, and grill, covered, for about 8 minutes. Flip the birds and let them grill, uncovered, for another 3 to 5 minutes. Flip them one more time and paint with a little sauce, let that sit a minute, then serve.
One note when grilling any duck:Watch for flare-ups that will happen when your bird starts dripping fat on the coals. There are two easy ways to handle this: Move the ducks away from the direct heat, and/or use a spray bottle with water to douse the flares.