Salsa Verde de Lupita

Ingredients

• 1 1/4 lb tomatillos
• 2 serrano peppers
• 1 to 2 cloves garlic
• 1/2 to 1 large white onion
• 1/2 bunch fresh cilantro
• 1 tsp sea salt
• fresh lime juice (optional)
• 1 to 2 avocados (optional)