I really don't have a recipe for this either, but it's based on what my mom did with a few changes.
Nectarines (about 2 pounds)- peeled and sliced into chunks into a saucepan
3/4 cup sugar
2 T butter
1/4 tsp ground cinnamon
All this goes into the saucepan and set on medium low heat. Stir often and be mindful of the heat - adjusting to make sure the fruit starts to break down, but not cook at too high a temp to get mushy. It's good if the mixture thickens as well.
This typically takes 15-25 minutes depending on how ripe the fruit is. I tend to pick a little firmer nectarine for this recipe. If the fruit mixture is not thickened enough 1 T of cornstarch dissolved in a little milk will help.
The biscuit topping is also simple.
1 cup self-rising flour
3 T unsalted butter, softened
1 t sugar (optional)
1/2 c milk
Mix biscuit topping together in a small bowl until blended, but do not overmix. Once fruit is complete, pour into a glass baking dish (This fits perfectly in a 8 x 8 glass baking dish.) and top with little spoonfuls of the biscuit mix. Bake at 375 degrees for 20-25 minutes.
This is wonderful warm or at room temperature.