Questions: Which step will keep food safe when preparing a casserole or make-ahead meal? Thaw on the counter before cooking. Make up to 5 days ahead and refrigerate until ready to use. Cook to a minimum of 165°F Cook directly from frozen:

The answer is the third one: Cook to a minimum of $165^{\circ} \mathrm{F}$.

Explanation for each option:

1. Thaw on the counter before cooking: This is incorrect because thawing food on the counter can allow it to enter the "danger zone" (40°F to 140°F), where bacteria can multiply rapidly, increasing the risk of foodborne illness.

2. Make up to 5 days ahead and refrigerate until ready to use: This is not recommended because keeping food in the refrigerator for up to 5 days can still allow for bacterial growth, especially if the refrigerator is not at the proper temperature (below 40°F). It is generally safer to consume refrigerated leftovers within 3-4 days.

3. Cook to a minimum of $165^{\circ} \mathrm{F}$: This is correct because cooking food to an internal temperature of 165°F ensures that harmful bacteria are killed, making the food safe to eat.

4. Cook directly from frozen: This can be safe if done correctly, but it is not always the best practice for ensuring even cooking. Some foods may not cook evenly from frozen, potentially leaving parts of the dish undercooked and unsafe.

Summary: The safest step to ensure food safety when preparing a casserole or make-ahead meal is to cook it to a minimum internal temperature of 165°F. This temperature is sufficient to kill harmful bacteria and ensure the food is safe to eat.