In a large saucepan, warm the olive oil and butter together over medium heat. When the butter has melted, add the onion and cook, stirring occasionally, until wilted, 3 to 4 minutes. Stir in the garlic and cook 2 to 3 minutes longer, stirring frequently and stopping before the onion and garlic brown.
Sprinkle the flour and continue cooking, stirring continuously, until the mixture turns a golden-blond color, 10 to 15 minutes. Then, whisking continuously, slowly pour in the stock until it is smoothly incorporated. When the mixture begins to simmer, stir in the cream. Let it return to the simmer. Remove from the heat, add the Parmesan, chicken base or bouillon cubes, lemon juice, and sugar, and stir until thoroughly blended.
Add the sour cream, spinach, artichoke bottoms, Monterey Jack cheese and Tabasco sauce, and stir until the ingredients are thoroughly combined and the cheese has melted. Transfer to a warmed serving bowl and serve immediately, accompanied by blue and white corn tortilla chips.
A vast majority of CPK employees list this dip as their own and their customers' favorite appetizer. If you like, try serving it with wedges of fresh-baked focaccia in place of the tortilla chips.
Recipe Source: California Pizza Kitchen - Pasta, Salads, Soups and Sides by Larry Flax and Rick Rosenfield