On a dry skillet, roast jalapeno or serrano chili until the skin is blistered and is tender. Place them in a bowl and cover with a plate or plastic wrap. Remove the skin and seeds, chop and keep ready.
In a mixing bowl, combine jicama, tomatoes, onion, roasted chilies and cilantro.
Pulse the roasted pumpkin seeds in a coffee grinder into a gritty powder. Then in a bowl whisk the pumpkin seed powder with lemon juice, agave, dried oregano, ground cumin and salt.
Pour the dressing over the vegetables and toss well. Serve the salad immediately.