Slice the squash in half, remove the seeds and place cut side up on a baking sheet.
Place into a 350°F oven for 25 minutes.
If you have trouble cutting the squash in half place the whole squash in the oven for 10 minutes, remove, slice in half, then place back in the oven for an additional 15 minutes.
While the squash is cooking, begin preparing the barley, risotto style.
Add 1 tsp of basil oil to a skillet over medium heat, add the chopped mushrooms and sauté for 5 minutes.
While the mushrooms are cooking, heat the vegetable stock to a boil in another pot.
Add the barley to the pan and begin ladling the stock 1/2 cup at a time into the mushrooms and barley until the liquid is absorbed (just like risotto!)
Continue ladling the stock into the barley until they are soft to taste, about 15 minutes.
While preparing the barley, also prepare the vegetables in another skillet.
Add 1 tsp of basil oil to a skillet over medium heat, then add the brussels sprouts, carrots and pearl onions.
Sauté for 5 minutes, then add the broccolini and 1/4 cup of water to lightly steam the vegetables.
Cook for 2-3 minutes, then add the spinach and cook for an additional 1-2 minutes.
At this point, the squash should be ready to come out of the oven, barley should be cooked perfectly and ready to fill the squash and the vegetables should be ready to top the dish.
For the final step, drizzle an additional tsp of basil oil on top.