Heat a pot of water to boiling and add sweet potatoes. Cook for about 10 minutes, until easily pierced with a fork.
Meanwhile, brown chorizo in a large skillet. Do not drain grease.
When the potatoes are ready, drain into a colander, then add potatoes to the chorizo and cook for about 5 minutes to crisp.
Warm tortillas in the oven, microwave, or by cooking lightly on a dry skillet.
Divide filling among tortillas. Halve and pit avocado, then slice thinly and add to tacos. Spoon on salsa, if desired.
If freezing, let filling cool to room temperature before putting in tortillas. Then, add filling, leaving off avocado, and wrap tortilla tightly. Place seam-side down on a parchment-lined baking sheet and repeat with remaining tortillas. Flash-freeze tacos for about 1 hour, then remove and wrap each in foil or plastic wrap. Store in freezer bags and reheat unwrapped in the microwave for about 2 minutes.