Take the pie crust out of the box. Leave it in the plastic and let it sit on your counter to soften up. An hour should do it.
You'll need a 9-inch fluted tart pan. Remove crust from package and lay it over the tart pan. Carefully ease the crust into the recesses of the tart pan. There will be about 1 inch of crust sticking over the top. Fold that over so the top of the crust lines up with the top of the tart pan. Poke holes in the crust with a fork to keep it from bulging up while baking. Look for cracks in the folds of the crust. If they are close to showing, try to push them back together with your fingers; otherwise your finished crust will have larger cracks when it expands as it bakes and your filling could leak later.
Bake according to package directions for 400 degrees for 7 to 9 minutes. Cool.
Meanwhile, put your cherries in the sauce pan with the sugar. Cook on medium high until the sugar melts and the mixture starts to bubble. Then add cornstarch one tablespoon at a time. You might need to sift your cornstarch into the mixture. It's a real pain to get the white blobs back out if the cornstarch does not mix in well. Continue to cook cherry mixture on medium. As it bubbles, it will get thicker with each addition of cornstarch. When it looks thicker, glossy and like pie filling, you are ready to let it cool down.
While the pie filling is cooling you can toast your (optional) coconut. This is not required as part of the recipe but it looks great on top of the cherries and adds more texture. Put the coconut on a cookie sheet. Bake in a 350 degree oven for about 7 minutes. Keep an eye on it. When coconut toasts it "goes fast." One minute it's not toasted, and the next the whole outer edge is brown. When this happens, take it out of the oven and just stir it up. All will be crispy and some of it will be browned.
Pour the tart filling in the crust. Spread it to the edges and sprinkle with coconut and slivered almonds. Leave a rim of the cherries around the edges so the red "pops." It will look great.