How can I add Soy Protein Isolate powder in Penne Pasta?

I have tried it with tofu by grinding it with tomatoes and cashews but it went horribly wrong cause silken tofu is very expensive for me. So now I am thinking of making sauce using tomatoes, soy isolate, cashews and garlic and when I add all the herbs in oil and pasta I'll add the sauce over the pasta instead of cooking it in oil first and then let it simmer. But I'm afraid what if I have to throw it away cause it will turn out terrible 🤣 if you have any sights, please share.

P. S. - I'm a vegan, so I wouldn't use milk or anything.