Heat the oil & cook the onion until it turns golden & transparent. Add the tomatoes & let them cook for 3 minutes. While they are cooking, roughly mash the peas with a fork.
Transfer the peas to the pan containing the cooking onion & tomatoes. Cook them for 5 minutes. Stir from time to time. Spoon in the ground peanuts & mix well. Season & continue to cook gently for 10 minutes. Serve with rice.