Make Ahead Tip: Cover and refrigerate the sauce (Step 1) for up to 3 days.
To warm tortillas, wrap in barely damp paper towels and microwave on High for 30 to 45 seconds or wrap in foil and bake at 300°F until steaming, about 5 minutes.
Note: Precooked shredded potatoes can be found in the dairy section of most supermarkets or near other fresh prepared vegetables in the refrigerated produce section. To make your own, halve 1 pound unpeeled baking potatoes; cook in lightly salted boiling water until slightly tender but still firm in the center, 7 to 10 minutes. Let cool on a clean cutting board. Shred using the large holes of a box grater.
2 starch, 1 vegetable, 1 medium-fat meat, 1 fat