1. Scrub the potatoes and prick three times with fork. Place them on a microwave bacon rack and cook on HIGH (1200W) for 5 - 6 minutes. Take them out and let cool. Then peel and mash.

2. Crack the eggs in a microwave safe egg poacher and add 1 teaspoon of water to each section. Cover and cook on HIGH (1200W) for 1 minute. Take the eggs out and cut into 1/2-inch cubes.

3. Place the low fat milk, bay leaf, sliced onions and cod cubes in a microwave safe bowl (2 1/2 liter or 3 quart). Cover with a vented microwave lid* and cook on HIGH (1200W) for 10 minutes. Take out the bowl, drain the milk, and set the milk aside.

4. To make <White Sauce>, place flour and butter in a microwave safe-bowl (1 liter or 1 quart), cover with a microwave lid and cook on HIGH (1200W) for 30-40 seconds. Take it out and stir until smooth. Gradually add the milk that was set aside, stirring constantly with a whisk until smooth. Add salt and pepper, cover and cook on HIGH (1200W) for 4 minutes. Stir until mixture is smooth.

5. Combine the white sauce, cod, sliced onions (discard the bay leaf), boiled eggs, shrimp, green peas and potatoes in a 1 1/2-liter or 1 1/2 quart casserole. Top with the cheddar cheese, cover with a vented microwave lid* and cook on HIGH (1200W) for 7 - 8 minutes or until it boils.

* When using plastic wrap as a cover, poke a hole in the center to release the steam.
* Milk based soup tends to boil over. If it starts to boil over simply remove the cover.

For how long you should cook with your microwave oven, see Cooking Time vs Wattage Conversion.
For more tips of using Microwave Oven, see Sachiko's Guideline to Microwave Cooking.