Preheat oven to 425°F. Add squash, zucchini and asparagus to a sheet tray. Drizzle with olive oil, salt & pepper and roast for about 10 minutes until vegetables are cooked through but not mushy.
Mash together butter, lime, and salt with a fork until blended. Or you can make into a log by rolling it up into wax paper or plastic wrap. Freeze until ready to use again.
In a heavy saucepan, bring water and milk to a boil over high heat. Add salt and pepper, reduce heat to medium. Add the polenta gradually, whisking constantly.
