Boil a large pot of water. When water is boiling, add orzo. Cook following package directions until al dente, about 8 min. Add peas for the last 2 min of cooking. Drain an d rinse with cold water. Drain well and cool completely, then pour into a large bowl. Stir in oil.
Add clam juice, zest, garlic, rosemary, saffron, salt and chili flakes. Bring to a boil over medium. Simmer for 5 min to infuse flavour. Set aside to cool. When clam juice mixture has cooled completely, pour over orzo. Cut tomatoes in half crosswise, then squeeze out seeds. Coarsely chop. Stir into orzo along with peppers and onions and lemon juice. Taste and add more salt, if needed.
Nutrition (per serving)
Salad will keep well at room temperature for two hours before serving.