Place 8 cups of water on stove in a large pot. Place on high heat.
While waiting for the water to boil, start cooking the alfredo sauce; angel hair pasta tends to cook fairly quickly so the sauce needs to be ready.
Place plant based milk in a pan, bring to a light simmer.
Add sour cream, 1 tbsp butter, onions, garlic, and oregano. Stir well and allow to sit on low heat covered.
As water starts to boil, turn heat to medium and add pasta to cook. Sprinkle salt in pot to prevent sticking.
While pasta cooks sift the tapioca or corn starch into sauce (if you do not have a sifter sprinkle in and stir immediately). Stir the sauce well. Add avocado oil.
Add diced tomatoes to the sauce and allow to simmer. Then turn off the heat.
Strain pasta and place in a serving dish, pour sauce over the pasta and mix. Sprinkle black pepper over the pasta.
