Toss roast pumpkin ingredients in a baking tray, space pumpkin cubes out into a single layer with wiggle room in between each cube. Roast at 220°C/430°F for 30 minutes or until lightly charred around the corners, on the top shelf of the oven. No need to flip halfway. (note 1)
Whilst pumpkin is roasting away, prepare the candied walnuts. In a small pan, add water and sugar on medium-high heat. Swirl the pan around until the sugar has dissolved. Add walnuts and coat by mixing walnuts around with a spoon or spatula.
Spread candied walnuts out onto a lined baking tray. Ensuring wiggle room in between each walnut so they don't come out stuck together. Roast for 5 minutes in the oven together with the pumpkin, on the middle shelf.
To make the vinaigrette, combine all ingredients into a small bowl and mix well with a teaspoon spoon for about 30 seconds. (note 2) Shake it out in a mason jar if you have one instead.
Once the pumpkin is roasted, allow it to cool down a little (so that it doesn't cook the leafy greens when tossed together).
To put the salad together, lay the spinach and rocket first onto the serving dish. Then, in the following order, pumpkin, goat's cheese (use a butter knife to cut into small pieces) and candied walnuts.
When ready to serve, drizzle vinaigrette dressing all over.