Add the walnuts and pumpkin seeds to a food processor or blender and process until finely ground. Transfer the ground walnuts and pumpkin seeds to a jar along with the ground flax seed and chia seeds. Pour in the almond milk, vanilla, extract, pure maple syrup, and sea salt. Stir well to combine. Seal the jar and allow it to sit overnight in the refrigerator (or at least 3 hours).
When ready to serve, either heat the porridge on the stove top or leave it cold. Serve with desired fruit, nuts, seeds, liquid sweetener, and additional non-dairy milk. My personal favorite toppings are almond butter, blueberries, pumpkin seeds, hemp seeds, honey, and full-fat coconut milk.
Notes
*Use any nut milk you'd like. For a creamier consistency, use equal-parts almond milk and full-fat canned coconut milk.