Heat the oil in a large pot over medium heat. Once the oil shimmers, stir in the onion and cook for about 5 minutes, until softened.
Add the chopped chard stems, the garlic, cumin, coriander and crushed red pepper flakes; cook, stirring, for 1 minute, then add the lentils and the broth.
Add the tomatoes, one at a time, crushing them with your hands over the pot, plus any juice that’s remaining in the can.
Add the bay leaf, salt and pepper; once the mixture is bubbling at the edges, reduce the heat to medium-low, partially cover and cook for 25 to 35 minutes, until the lentils are tender; check the tomatoes during this time and break them down further with a spoon.
Increase the heat to medium-high; stir in the macaroni. Once the liquids come to a boil, reduce the heat to medium-low, partially cover and cook for about 10 minutes, at which point the pasta should be nearly done.
Discard the bay leaf, then stir in the Swiss chard leaves. Cook for 5 minutes, then taste and season with more salt and/or pepper, as needed.
