We ate corundas in Morelia (more on that later) and I wanted to make them at home because I loved them. I didn't have fresh corn leaves, nor did I have banana leaves since they're only sold in a few places in Guadalajara. But I did have plenty of dried corn stalks for regular tamales and they're not the same, but they worked.
Corundas are unfilled triangular tamales topped with crema and salsa. Here's the basic idea of how I made them. I think it's about as hard to give exact measurement for tamale masa as it is for making bread dough so nothing here is exact but it should make sense if you've made tamales before. And really, masa is forgiving.
Soak a bunch of corn husks, or banana leaves, or use green corn leaves (not husks) if you have some growing in your garden, or your neighbor's.
Mix a kilo of fresh masa (or reconstituted masa) with a few tablespoons of butter or lard or oil and just enough chicken broth or milk or water to make a spackle-like consistency, or a rather thick batter that will hold together. Add some salt- maybe a teaspoon and a bit of baking soda and maybe 1/2-1 tsp of baking power. Mix that by hand or in a machine or with a hand-held mixer till it's fluffy.
Get a big pot of water boiling with a steamer in it. If you're using a crockpot, start that earlier.
You want relatively thin strips of whatever you're using to wrap your tamales. Take a blob of masa about the size of a squash ball and try to shape it into a triangle. If you have something long to wrap it in, wrap it around the three sides consecutively. If you're using dried corn husks, tear them into small strips lengthwise and wrap the masa as best you can. Or do it in whatever shape makes you happy if the triangles are giving you a headache. When all the masa is wrapped, put the tamales in the steamer. You should have about 15. They'll take about an hour to cook at the most (or 3 in a crockpot) and remember to check the water level.
The crema is an easy topping. For the tomato sauce, blend 5-6 tomatoes, a couple of cloves of garlic, and a hunk of onion. Pour that into an oiled skillet and fry for a few minutes. You can add some shredded chicken if you like and salt to taste.