Set a large deep skillet with a lid over medium heat. Add the olive oil and let it warm for about 30 seconds.

Add the chopped onion and 1/2 teaspoon of the salt to the skillet. Cook for 4 to 5 minutes, stirring often, until the onion is soft and lightly golden at the edges.

Add the minced garlic to the skillet. Cook for 30 seconds, stirring, until it smells fragrant.

Add the bulgur to the skillet. Stir for 1 to 2 minutes so the grains are coated in oil and smell lightly nutty.

Pour the vegetable broth into the skillet. Use a wooden spoon to scrape the bottom of the pan so any onion bits are mixed into the liquid.

Stir the capers and half of the lemon zest into the skillet. Raise the heat to medium-high and bring the liquid to a boil.

When the broth is boiling, reduce the heat to low and cover the skillet. Cook for 10 minutes.

Uncover the skillet and check the bulgur. Most of the liquid should be absorbed, and the grains should look swollen and nearly tender.

If the skillet still looks very wet, cook the bulgur uncovered over low heat for 1 to 2 minutes. If the bulgur still feels too firm, add 2 tablespoons of water, cover the skillet again, and cook for 2 more minutes.

Scatter the frozen peas over the bulgur in the skillet. Cover and cook for 2 minutes, until the peas are hot.

Turn off the heat. Fluff the bulgur and peas with a fork so the grains separate a little.

Open the tuna cans and drain them if needed. Add the tuna to the skillet in large flakes.