Split Pea and Sweet Potato Dal

Split Pea and Sweet Potato Dal
(once again, don't know where it came from)

1 Tbs. EVOO
1 lg. onion chopped
2 tsp. black mustard seeds
1 tsp. Fenugreek seed (optional)
1 jalapeno minced (optional)
2 Tbs. minced Ginger
4 tsp. Ground coriander
1 Tbs. Cumin
1 tsp. Turmeric
6 cups water
2 cups yellow split peas (sometimes I use brown lentils)
1 med. Sweet potato cut into 1/2 inch dices
After cooking add:
2 Tbs. fresh Lemon juice
1 Tbs. Agave or sugar
1 Tbs. Salt
Cayenne pepper