Heat oil to moderately high. Add onion, bell pepper, and garlic to pan; cook, stirring, until onion turns gold. Chop and stir in undrained tomatoes. Add lemon juice, parsley, and salt, and stock. Bring to boil; add saffron and simmer 5 minutes. Add rice and simmer. Skin and bone chicken breasts; remove all visible fat and thinly slice meat against the grain. 5 minutes before rice is done, add chicken and stir well. When done, uncover and garnish with peas, pimiento and parsley sprigs. Nutritional values per serving, Not including values for stock since they will vary widely: 305 calories, 37.65 gm protein, 70.5 gm carbohydrate, 5 gm fat, 14.8% of calories from fat, 40 mg cholesterol, 812 mg sodium. To calculate in nutritional values of whatever stock you use, multiply the per-cup values by 0.875 and add to the above numbers.