Heat a large sauté pan to low heat and add 1 tbsp. of oil (if you are oil-free see notes). Add pumpkin seeds and chile guajillo and cook until golden brown, remove from pan and set aside. Add onion and garlic to pan and cook until golden brown (keep garlic whole).
In a small pot, simmer the corn in water until tender, about 2-3 minutes. Strain and reserve ¼ cup of the corn cooking liquid, and 1 tbsp. of corn kernels for garnish.
Place the corn, chile guajillo, pumpkin seeds, onion, garlic, tomato, and ¼ cup of the corn water and blend until smooth.
Add 1 tbsp. of spearmint, season with salt and pepper, and blend again.
Pour the sauce into a medium sauce pot, set to medium-low heat, and bring to a simmer. Simmer for 3-5 minutes, then turn off heat, cover and keep warm.