Cook the farro: Fill a medium saucepan with water and bring it to a boil over high heat.

Add 1 teaspoon of the kosher salt to the boiling water. Add the farro to the saucepan and stir once.

Boil the farro for 10 minutes, adjusting the heat as needed so the water stays at a steady boil.

Start the dressing: While the farro cooks, put the olive oil, Dijon mustard, lemon zest, 2 tablespoons of the lemon juice, 1/4 teaspoon of the black pepper, and 1/4 teaspoon of the remaining kosher salt into a large serving bowl.

Add the chopped shallot to the bowl and whisk until the dressing looks smooth. Let the shallot sit in the dressing while the farro finishes cooking so it softens slightly.

Prep the salmon: Open the cans of salmon, drain them well, and put the salmon on a plate. Use a fork to break it into large flakes, removing any large pieces of skin or bone if you like.

Finish the grain and vegetables: When the farro has cooked for 10 minutes, taste a grain. Keep boiling it 1 to 2 minutes more if needed, until it is tender but still slightly chewy in the center.

Stir the frozen peas into the saucepan with the farro and cook for 1 minute, just until the peas are hot.

Set a colander in the sink and drain the farro and peas well.

Return the empty saucepan to low heat. Add the spinach and 1 tablespoon of water to the saucepan.

Stir the spinach for about 1 minute, until it has wilted down and turned bright green.

Put the drained farro and peas back into the saucepan with the spinach. Stir for 30 seconds, just until the spinach is mixed through.