Best Tostada Recipe - How to Make An Authentic Tostada

Ingredients

• 1/2 small red onion, sliced
• Juice of 1 lime
• 2 tbsp. butter
• 2 tbsp. vegetable oil, plus more for frying
• 1/2 small yellow onion, minced
• 1/2 tsp. dried oregano
• 1/2 tsp. chili powder
• Kosher salt
• Freshly ground black pepper
• 2 (15.5-oz.) cans pinto beans, drained and rinsed
• 6 corn tortillas
• 1 1/2 c. cotija, crumbled
• 1 avocado, sliced
• 4 radishes, thinly sliced into rounds
• 1 jalapeño, thinly sliced
• 1/4 c. cilantro leaves
• 1 lime, sliced for serving