½lb.Linguine or favorite pastacooked according to package directions
*If soaking dry beansstart with 1 cup before soaking.
In a medium-sized, heavy bottomed pot, cook onion and peppers (if using fresh) in melted butter until tender, adding garlic at the last minute. Stir in flour and pepper and cook two minutes. Add the milk all at once. Cook and stir over medium heat until bubbly and thickened, taking care not to scorch the bottom.
Cook one more minute, then add cheese and stir to melt. Add the beans and canned chiles (if using canned) and stir to heat through. Feel free to add extra milk at any point if the sauce is too thick for your tastes.
Serve over linguine or your favorite pasta. You might include steamed veggies right in the sauce for an all-in-one meal.
For the bean haters of the world: If you use an immersion blender and whiz the sauce, the beans (and their taste) disappear. You might want to add a bit of extra milk to thin it out, up to 1/4-1/2 cup.