1. Make sauce: In a medium saucepan, heat 1 1/2 tablespoons oil over
medium. Add flour and cook, whisking occasionally, 1 minute. Add broth,
chili powder, chipotle and adobo sauce, and 3/4 cup water; bring to a
boil, whisking constantly. Reduce heat, and simmer until lightly
thickened, about 10 minutes.
2. Make filling: In a 10-inch nonstick skillet, heat remaining 1/2
tablespoon oil over medium-high. Add onion, garlic, and beef; season
with salt and pepper. Cook, stirring, until cooked through, about 8
minutes.
3. Preheat oven to 350 degrees. (If freezing, don't place any sauce
in baking dish; see To Freeze, below left.) Spoon 1/4 cup sauce in
bottom of an 8-inch square baking dish. Set aside. Make enchiladas:
Stack tortillas; wrap in foil, and warm in oven, 10 minutes. Fill each
with a heaping 1/4 cup beef mixture and 2 tablespoons cheese; tightly
roll up.
4. Raise oven heat to 450 degrees. Arrange enchiladas, seam side
down, in baking dish. Top with remaining sauce; sprinkle with cheese.
Bake, uncovered, until hot and bubbly, 15 to 20 minutes. Let cool 10
minutes before serving. Serve garnished with cilantro and, if desired,
a green salad.
5. To freeze: make sauce and enchiladas; arrange enchiladas
in baking dish without sauce (so tortillas don't become soggy). Place
sauce in an airtight container. Cover dish with plastic wrap and foil.
Label, date, and freeze enchiladas and sauce. Use within 2 months; bake
without thawing.
6. To bake from frozen: Thaw sauce in refrigerator overnight.
Preheat oven to 450 degrees. Remove foil and plastic wrap from baking
dish. Pour sauce over top, and sprinkle with cheese; cover with foil.
Bake 30 minutes. Uncover; bake until lightly browned and bubbly, about
15 minutes. Let cool 10 minutes; serve.
7. If baking right away: Spoon 1/4 cup sauce in the bottom of baking dish; pour the rest over the enchiladas.
