Preheat oven to 425 degrees.
Toss squash with a few tablespoons olive oil and salt and pepper.
Spread in one layer on a rimmed baking sheet and bake for 30 minutes.
While squash is cooking...
Pour chicken broth into a large pot and heat to boiling on stove. Reduce to a simmer.
In a large deep skillet, melt butter on medium-high.
Add garlic and cook for 2 minutes.
Pour in rice and coat with butter.
Add white wine and cook until most of wine is absorbed, stirring so rice does not burn.
Gradually add chicken broth, 1/2 cup at a time, while stirring intermittantly. Broth should mostly absorb before adding the next cup.
Discard bay leaf and remove risotto from heat.
Stir in parmesan cheese, lemon juice and zest, and roasted butternut squash.