In the Meat & Seafood Departments
Identify markets with good butcher and/or seafood counters, where you can order exactly the amount of meat, chicken, fish or seafood you need. If your local supermarket only sells prepackaged meats that are more than you'll use right away, wrap the extras tightly and freeze them. A vacuum sealer is a great way to ensure the quality of frozen food.
The 6- or 7-ounce cans and pouches of tuna, salmon, sardines and crab are perfect for two.
If you need shrimp, buy peeled frozen tail-on shrimp. These are usually sold in 2-pound bags but you can take out what you need when you need it without having to defrost the whole amount. Some supermarkets also have bulk freezer bins of shrimp.
A 2-pound bag of mussels yields about 6 ounces cooked meat, the appropriate portion for two diners.