This is a good filling for tamales. It's very simple to make and also very tasty.

1. Roast the poblano peppers in a comal or griddle.
2. When they are roasted put the poblano peppers in a plastic bag wrap in paper towels for about 15 min.
3. Meanwhile, roast the tomatillos and serrano peppers in a skillet or comal.
4. Blend roasted tomatillos, serrano peppers, onion, garlic, cilantro and salt.
5. Peel the poblano peppers and cut them into medium-thick strips (rajas) and set aside.
6. Cut long medium-thick strips of panela cheese and set aside.
7. Slice the onion into half-moon slices.
8. Add a little oil to a skillet at medium-high heat. Saute the onion and then add the green sauce and stir continuously until it changes color to a darker green.
9. Add the poblano peppers to the sauce and reduce heat to medium for about 3-5 minutes.
10. Finally, add the cheese strips, stir and remove from heat.