You will need 2 rimmed baking trays/sheets for this recipe, unless you have a really big oven with a tray to match!
Pre heat oven to 190c/ 375f.
Place chopped pumpkin on the first baking tray in a bit of a pile, drizzle over 2 tsp of olive oil then mix with your hands to coat pumpkin well with oil then spread out pumpkin on baking sheet as well spaced as you can, sprinkle over salt & pepper to taste and roast for 15 mins.
Meanwhile, peel & cut each spanish onion into 12 wedges, roughly chop the bacon, and halve any large cherry/mini tomatoes but leave the others whole.
Take the second baking tray, place the onion, bacon & tomatoes in a pile on the tray, drizzle over 1 tsp of olive oil then mix with your hands to coat then evenly spread out vegetables on baking sheet.
After 15 mins, rotate baking tray of pumpkin in the oven if it needs it, then add second baking tray of vegetables and bake everything for a further 25 mins.
While the vegetables are roasting, make the dressing by combining mustard, lemon juice, garlic infused olive oil, red wine vinegar and salt and pepper to taste.
When cooking time is up, combine pumpkin with other vegetables, adding basil leaves & dressing, mixing lightly to combine if needed then serve topped with extra basil.