Scrumptious, easy casserole
Starch selection dictates whether a casserole holds its geometry or collapses into soup. Russets yield a high-amylose mash that absorbs added dairy substitutes effectively, whereas waxy red potatoes retain moisture and resist mashing, resulting in a fractured interior texture. Freezing changes plant cell walls permanently, meaning frozen spinach requires rigorous mechanical pressing in a cloth towel to remove excess liquid before incorporation. Without this pressing step, the trapped water dilutes the fats in the dairy-free sour cream and prevents proper emulsification during the initial twenty-minute bake at 400 degrees Fahrenheit. Substituting fresh spinach introduces raw moisture that must be sautéed away completely prior to mixing, altering the baseline hydration ratio established by the frozen variant. Plant-based cheeses melt differently than dairy counterparts because they lack casein protein networks, requiring precise thermal exposure during the final ten-minute cheese-melting phase to prevent oil separation. Onions softened residual-style in hot potato water rather than boiled directly maintain structural crispness and sulfurous bite, contrasting against the dense starch base. Adjusting milk quantities by tablespoons controls the viscosity of the mash before folding in broccoli and carrots, ensuring uniform heat distribution throughout the two-quart baking dish.