Hey Sara,
I normally make fruit toppings in a skillet---I just chop the fruit, add a splash of lemon juice to prevent browning, spices if I want (usually ground cardamom or a little bit of cinnamon), and saute. I add sugar, then boil the mixture down into a thick sauce.
I think you can make the same exact thing in a healthier way by adding just a tiny bit of sugar (or none at all, but many fruits will be somewhat tart without it), bringing everything to a boil for a couple of minutes to cook the fruit through, and then remove from heat and add a little bit of corn starch mixed in water in order to thicken it. The downside is that cornstarch will give the mixture a little bit of a cloudy appearance.