Black Bean, Spinach and Mushroom Burrito

1 onion, chopped fine
1/2 pound mushrooms, chopped fine
1 tablespoon vegetable oil
1 bunch spinach (about 1 pound), coarse stems discarded,
washed well and spun dry
2 garlic cloves
1/4 cup water
1 cup canned black beans, rinsed well and drained
1 teaspoon fresh lemon juice
2 scallions, chopped fine
3/4 cup coarsely grated pepper Jack cheese (about 5 ounces)
1/2 cup canned mild enchilada sauce
two 10-inch or four 8-inch flour tortillas
Accompaniment: Sour cream

In a heavy skillet cook onion and mushrooms in oil over moderate heat, stirring, until golden. Add spinach and garlic and cook, stirring, until spinach is wilted, about
30 seconds.
Stir in water, beans, lemon juice, scallions, pepper Jack, and salt to taste and cook, stirring, until cheese is melted.In a small saucepan heat enchilada sauce.
Heat a dry skillet (large enough to hold 1 tortilla) over moderately high heat until hot.
In skillet heat tortillas, 1 at a time, turning frequently, 30 seconds, or until softened, and transfer to a work surface.
Divide filling between tortillas and roll up burritos.
Spoon sauce over burritos and serve with sour cream.

From Gourmet Magazine