In a large pot with a steamer insert, bring salted water and a splash of beer to a boil. Steam broccoli until crisp-tender, about 4 minutes. Keep warm.
In a saucepan over medium heat, melt butter and cook onion and garlic until softened, about 5 minutes. Stir in ricotta cheese, beer, and sour cream until smooth and heated through. Add salt and white pepper. Spoon the sauce over steamed broccoli. Garnish with chives and serve.