pie perplexity

I have a fridge full of strawberries and rhubarb and a strong desire to make a pie. Naturally I found recipes via TKL, but to my consternation they all called for tapioca as a thickener. I don't have any around and don't feel like a big trek to the grocery. Does anyone know how I can substitute cornstarch? There are several strawberry pie recipes available that use cornstarch, but they are of the no-bake variety. I am pretty sure a filling that contains rhubarb needs to go in the oven. Or else I'll need to cook the rhubarb on the stovetop, but since I rarely use rhubarb, I don't know how to approach this.

Perhaps there is no such thing as a pie thickened by cornstarch that has a baked filling? I know that cornstarch does funny things if you get it TOO hot.