Rinse and sort through peas.
In a deep pot, bring 2 quarts water to boil over high heat. Add peas. Let water return to boil; then boil uncovered for 2 minutes. Remove pan from heat, cover and let stand for 1 hour.
Drain and rinse peas, discarding cooking water.
In crockpot, combine onion, garlic, green chiles, cumin pepper, baking soda and chipotle chile. Stir in peas; pour in remaining 3 cups water. Cover and cook on LOW until peas are tender to bite - 9 to 10 hours).
Remove and discard chipotle chile; stir in rice and tomatoes.
Increase heat to HIGH; cover and cook until rice is tender - 45 to 55 minutes more).
Season to taste with salt.Servings: 6