This is one of our favorite ways to enjoy leftovers from a big Mexican meal, particularly if you still have a few ancho chilies left in the bag after you cook. Rehydrated ancho chilies can be stuffed with anything really, but a smooth, crumbly cheese like ricotta, goat cheese or feta makes a more satisfying texture than a melty cheese like cheddar.
This is also a great way to use up leftover Spanish Rice, although it can be made with freshly cooked rice as well.
To make the escabeche, heat olive oil in a pan on medium. Add sliced onion and sauté, gently, until softened, about 5 minutes. Add sugar, salt, wine vinegar, wine or water, and tarragon. Simmer gently for 15-20 minutes. Remove from heat and set aside.
Meanwhile, toast the ancho chilies on a hot pan until supple, about 10-15 seconds on each side. Using a small, pointy knife, carefully cut a slit into the side of each chile and remove as many seeds and as much placenta as possible. Try to keep the stems in tact, but remove if necessary.
Place seeded anchos in a large bowl, then cover with the onion escabeche. You may need to weigh the chilies down with a plate to ensure they are submerged. Soak until fully rehydrated, about 30 minutes.
Meanwhile, toast the unpeeled garlic cloves on a hot pan until soft, about 10 minutes. Remove from heat and peel.
Place garlic cloves in a bowl and smash with a fork. Add ricotta, rice and pepper, then mix until thoroughly blended.
When rehydrated, remove anchos from the escabeche. Try to drain them as well as possible. Stuff each chile with the filling.