Heat the oil in a large, deep skillet on medium-high heat, and saute the garlic, onion, and bell pepper and a good pinch of salt. Cook until the onions start to turn golden on some of the edges.
Mix in the gochujang paste and toss with the veggies for just a minute, then add the vegetable broth to the pan, stirring until the paste is dissolved in the broth.
Add the spaghetti, pressing the spaghetti into the liquid and spreading it out as much as possible in the pan.
Cover the skillet, bring the mixture to a boil, then reduce the heat to medium-low and simmer for 8-12 minutes or until the pasta is tender (see the cooking time on your pasta's package for how long to cook to al dente). Make sure to stir the pasta after 5 minutes to prevent sticking. How long it needs to cook will depend on the spaghetti you're using as well as your stove and pan.
Remove the lid, reduce the heat to low, and add the cashew cream, stirring to combine. Add salt and lime juice to taste at this point. Stir in the greens, mixing until they wilt.
Taste and adjust the seasoning, as needed. Serve immediately, topped with red pepper flakes.
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Notes
Make sure that you really press the spaghetti into the broth mixture well and that you stir it once during cooking. That will help keep the spaghetti from sticking together.Feel free to change up the veggies! Add slower-cooking veggies during the sauté and quick cooking veggies at the end. Frozen vegetables are also fine to use. Thaw them and then add them at the end, where the spinach is added in the directions above.