First cook some whole wheat pasta and put it aside, covered, so it won't get cold.
1 tbsp olive oil
a few cloves of garlic
lashings of olive oil
balsamic vinegar to taste
half a bag of spinach (could be a bag, though, if you want, it cooks down to nothing)
a handful of large cherry tomatoes (again, could be more, I used what I had)
salt to taste
Heat the oil, add the onion and garlic and sizzle over high heat until soft. Reduce the heat slightly and add the spinach, more olive oil and balsamic vinegar. When it has cooked down (a few minutes later) add the remaining ingredients plus the pasta, stir it until it's heated through, and serve (or refrigerate to eat for lunches over the week, if you're me).
I would add the tomatoes right at the last minute if I had to do this again, they started to "cook" a bit too much for how long I had them in last night -- skins coming off, going mushy, etc, which was not what I had in mind as this is not a pasta with tomato sauce but with tomatoes. But it's down to your taste, I guess.