For the hollandaise, in a small saucepan, melt the butter over medium-low heat. While the butter is melting, whisk the egg yolks, lemon juice, water and hot sauce together in a medium bowl until thoroughly combined. Once the butter has melted, add a tablespoon of butter to the egg mixture, whisking vigorously as you add it. Add another tablespoon of the melted butter to the bowl and again whisk vigorously as you add it. Pour the egg mixture into the small saucepan and continue to whisk vigorously as you add it. Continue to whisk until the hollandaise JUST begins to thicken, about 3-4 minutes. As soon as it begins to thicken, add the gruyere cheese and season with chili powder, salt and pepper to taste. Remove from heat immediately once the cheese has melted.