Preheat oven to 425 degrees F (218 C) and line a baking sheet with parchment paper.
Add potatoes, tomatoes, red onion, and green bell pepper to the baking sheet and drizzle with olive or avocado oil. Add the Italian herbs, garlic powder, salt, and red pepper flakes (optional), and toss well until evenly coated.
Roast for 20-25 minutes until the potatoes are golden brown, the onions are slightly caramelized, and the tomatoes are beginning to burst.
When the veggies and sausage are done, divide between serving bowls and top with sliced avocado, parsley, and hot sauce (all optional). Leftovers keep in the refrigerator for 3-4 days. Tempeh sausage can be frozen for up to 1 month.
Reheat leftovers, covered, in the microwave or oven (in an oven-safe baking dish) or on the stovetop over low heat until warmed through.
Video
Notes
*Nutrition information is a rough estimate calculated without optional ingredients.