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Slow Cooker Caramelized Onions Pasta

This indulgent vegan pasta dish delivers a deep, savory-sweet flavor through the slow caramelisation of onions. Enriched with umami miso, savory vegan cheese, and the silkiness of pasta water, it creates a luscious sauce that clings beautifully to each strand. Perfect for a cozy, satisfying meal that requires minimal ingredients yet offers maximum depth.
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Prep Time 15 minutes
Cook Time 35 minutes
Total Time 50 minutes

Ingredients
  

  • 1/4 cup grated vegan parmesan or plant-based cheese
  • 1 tbsp vegan butter or olive oil for caramelising onions
  • 1 tbsp white miso paste
  • Salt to taste
  • 1/2 tbsp vegan butter or olive oil for mushrooms
  • 1 large yellow onion peeled and thinly sliced
  • Water as needed
  • 1/2 cup reserved pasta cooking water or more as needed
  • 1/2 lb dry pasta spaghetti or linguine recommended
  • 1/2 lb mushrooms of choice thinly sliced (button mushrooms suggested)
  • Pinch of salt
  • Fresh parsley or basil chopped (for garnish)
  • Chili flakes for garnish

Instructions
 

  • Heat a thick-bottomed pan or Dutch oven over medium heat and melt the vegan butter or pour in the olive oil. Introduce the sliced onions and sauté gently on medium to medium-low heat for 30 to 40 minutes, stirring at regular intervals. Add a splash of water midway to deglaze the pan and sprinkle a pinch of salt to enhance the flavor. Once golden and fully caramelised, transfer the onions from the pan.
  • While the onions are cooking, bring a large pot of water to a boil. Salt the water generously, then add the pasta. Cook until al dente and reserve at least one cup of the starchy cooking water.
  • Return to the same pan and heat the vegan butter or oil. Add the mushrooms and sauté over medium-high heat until browned and tender.
  • Reintroduce the caramelised onions to the pan with the mushrooms. Add the drained pasta, miso paste, salt to taste, vegan cheese, and a portion of the reserved pasta water. Stir continuously until the sauce thickens and envelops the pasta. Adjust seasoning or liquid as needed for consistency.
  • Finish by garnishing with chopped parsley or basil and a sprinkle of chili flakes. Serve immediately for optimal taste and texture.