Start by preparing the rice, but do not add butter or margarine to them.
Meanwhile, clean and prepare your shrimps for cooking. Remove the heads and shells of the shrimps. As you de-vein the shrimps, you can let the tail part of the shell on, if you want.
Pour one teaspoon of olive oil in a non-stick 12-inch skillet and heat it over medium-high until it is just hot.
When the oil is hot enough, add diced onion to the skillet and reduce the heat to medium. Cook the onions until they are tender and translucent (about 5 to 8 minutes) while stirring occasionally.
When the onion slices are tender, add curry powder and cook for another minute, stirring constantly.
Transfer the onion mixture to a small bowl and set it aside.
Set the skillet on the stove again and increase the heat to medium high. Add the remaining one teaspoon of olive oil to the skillet and add mustard seeds to it. Cook the mustard seeds for a few seconds and then add shrimps.
While stirring frequently with a wooden spoon, sauté the shrimps for 3 to 4 minutes or until they are opaque throughout.
Once the shrimps are done, return the onion mixture to the pan and toss.
Add coconut milk, peas, carrots and salt and allow it to simmer on low heat for a couple of minutes.
Your shrimp curry is ready. Serve it over rice and sprinkle cilantro if you like.