Cook pasta according to package directions.
Using a whisk, mix the almond butter, nutritional yeast, and water. Cut smoked tempeh into small cubes, to represent "bacon". Peel onion and chop finely.
Heat olive oil in a pan. Sautée smoked tempeh in it for about 5 minutes, until browned and crisp. Add onion and fry for another 2 minutes. Then add almond butter mix and lemon juice. Add pasta water and let carbonara sauce boil briefly and thicken. Toss edamame, or other vegetables, if using it. Season with salt (or miso paste) and pepper to taste. Simmer until desired consistency and thickness is reached.
Toss the cooked pasta in the sauce. Serve and optionally drizzle with a little more olive oil.