Economical and simple midweek dinner for two. The tasty sauce will stand the addition/substitution of other veg: sweetcorn, courgettes, leeks, peas etc and can be made with bacon and/or any other meat (in small slices or cubes) or without meat. Puy lentils, chickpeas, borlotti, haricot, black eyed or any kind of cooked beans may be added in place of bacon to provide protein.
Do not overcook the pasta (or the veg/beans): it will continue to cook while the other ingredients are incorporated. Stir GENTLY when mixing it all together: You want the pasta and veg to maintain their integrity. Use any green veg (e.g. spinach, broccoli, peas) in place of (or in addition to) the green beans. Use fresh or frozen: just ensure it is almost but not quite 'done' before adding it to the pasta.