I learned, or relearned, an important lesson last night: that with pasta sauces, less is usually more. Throwing in further ingredients may bump up one's daily vegetable intake, but does not necessarily improve the dish. Instead of the shallot below, I used a whole red onion; it was not a particularly good onion, and it overwhelmed the other ingredients with its mediocrity.
This is a version, for one person, of the rigatoni and spinach idea. Again, a tubular shape such as rigatoni, or penne, would work well.
1 shallot, chopped
1/2 clove garlic, chopped
Olive oil, or oil and butter
1 or more dried chillis, whizzed
10 button mushrooms, sliced
2 anchovy fillets
5 tbsp double cream
Parmesan, to taste
125 g penne or rigatoni
Soften the shallot and garlic in a little olive oil, or oil mixed with butter, for about five minutes. (If you use butter only, you have to cook the shallot very gently, and be careful that it does not catch.) Tip in the chillis and mushrooms, turn up the heat, and keep stirring. After a minute or two, the mushrooms will disgorge liquid; cook, turning up the heat if necessary, until it evaporates. Turn down the flame. Stir in the anchovies and cream, and simmer, stirring in order to help the anchovies to dissolve, until the sauce thickens.
Meanwhile, cook the pasta according to the packet instructions -- but don't rely on the timings. Taste it, and drain when it still has a hint of firmness (al dente). It will carry on cooking for a bit.
Stir the pasta into the sauce, with Parmesan, if you like.