Trim, peel, and chop <quantity>1</quantity> onion into medium pieces

Peel and chop <quantity>2</quantity> potatoes into medium pieces

Place the onion and potatoes to a small saucepan

Season with salt to taste and cover with water

Bring to a boil over medium-high heat and cook until the potatoes are soft enough to be mashed

Chop <quantity>2</quantity> tomatoes into small pieces and reserve

Strain the onion and potatoes, and transfer them back to the saucepan. Reserve the liquid

Add <quantity>3<unit>cups</unit></quantity> of thawed, frozen green peas

Add <quantity>3½<unit>tbsp</unit></quantity> of olive oil and <quantity>2<unit>tbsp</unit></quantity> of white wine vinegar

Season with salt and ground black pepper to taste

Blend until the ingredients are crushed but still slightly chunky

Add the chopped tomatoes and mix to combine. The green pea guacamole is ready

Mix <quantity>1<unit>cup</unit></quantity> of cream cheese and <quantity>⅔<unit>cup</unit></quantity> of mayonnaise until homogeneous

Cover it with plastic wrap and take to the refrigerator to reserve

Finely chop <quantity>¼<unit>cup</unit></quantity> of dill

Finely chop <quantity>2<unit>tbsp</unit></quantity> of parsley

Trim, peel, and small dice <quantity>1</quantity> red onion

Boil <quantity>200<unit>g</unit></quantity> of crayfish for 5m over medium-high heat. Remove the meat from the tail and claws

Dice the crayfish into small pieces. Reserve a small amount on the side

Add <quantity>½<unit>cup</unit></quantity> of mayonnaise and <quantity>½<unit>cup</unit></quantity> of crème fraîche into a bowl

Add most of the crayfish. Add the red onion, the dill, and the parsley

Season with black pepper powder and salt to taste

Mix it. The crayfish dip is ready

Slice <quantity>1</quantity> sourdough bread loaf and cut rounds using a ring cutter

Spread an even layer of the Green Pea Guacamole on the bread and cover it with another round slice

Spread the Crayfish Dip evenly over the slice, and add <quantity>1</quantity> more slice on top of it

Cover the layered sandwich with the cream cheese and mayo mix using a spatula

Start garnishing the sandwich with fresh herbs to taste, a cucumber ribbon and a slice of medium-boiled egg

Add smoked arctic char and cooked shrimp to taste. Finish with trout roe to taste on top

The layered seafood sandwich is ready! Enjoy!