Pasta with Crab and Spring Onions

Spring brought spring onions?aka Mexican onions in the western US. They look like overgrown scallions, with a big bulb and a sweeter flavor than yellow onions. That turned our thoughts to a can of crab sitting in our pantry. In an earlier use, one of the same cans had ruined a pizza. The crab was very strongly flavored and we'd balanced it poorly, leading to a fishy pie that could only be saved by a thorough drenching in hot sauce. (A crude but effective method.) Green onions are a better option for mellowing out crab, especially if you plan on tasting the crab.

Pasta with Crab and Spring Onions

1 can crab
2 large spring onions
1-2 cup milk (1% is fine, but add a small amount of half-and-half; whole milk works too)
1 tbsp butter
3 tbsp or so cream cheese
¼ cup grated parmesan
½ lb spaghetti
Flour

1. Bring salted water to a boil and cook your pasta al dente.
2. Meanwhile, finely chop the white bulbs of the onions, set aside. Then chop the greens and set aside.
3. Add butter to a hot pan, add the white part of the onion.
4. Cook for several minutes, then stir in 1 tbsp flour, adding more butter as necessary. Cook for about 1 minute.
5. Add milk, stirring vigorously to incorporate flour. Bring up almost to a simmer.
6. Add cream cheese and dissolve.
7. Add parmesan cheese and dissolve (to taste).
8. Drain pasta (reserving water to loosen sauce if necessary).
9. Combine pasta in sauce, adding extra water if necessary.
10. Toss in most of the green part of the onions.
11. Serve garnished with cheese and green onions.