This pasta dish is full of bright, sweet, tart, and savory flavors. Both tomato paste and sun-dried tomatoes pack big tomato flavor and briny feta helps balance the sweet and acidic sauce. A bit of basil lends an herbal note for this delicious side.
Rinse the kelp noodle pasta under hot water in a fine mesh strainer. Let drain in the sink while you prepare the sauce.
Heat a large pan over medium-high heat. When hot, add the avocado oil and onion. Cook, stirring often until the onions are soft and translucent, 5-10 minutes. Add the garlic and cook until fragrant, stirring for about 1 minute more. Stir in the tomato paste, soy sauce, monk fruit, water, sun-dried tomatoes, basil, and balsamic. Simmer for another 10 minutes to let the flavors meld.
Add the pasta and stir to coat completely in the tomato sauce. Cook for another 5 minutes, stirring often. Taste and adjust seasoning with more salt, balsamic, or soy as desired. The sauce should be bright, sweet, and a bit tart. Drizzle with olive oil and sprinkle feta over top, stirring just a bit to incorporate some. Serve warm.