Black Bean and Pepper Tostadas - AMY'S GARDEN

Ingredients

• 3 medium bell peppers, thinly sliced (preferably at least one red and one yellow)
• 1 medium yellow onion, sliced
• 1/2 cup extra-virgin olive oil, plus more as needed
• 2 teaspoons kosher salt, plus more as needed
• 1 tablespoon chopped fresh sage
• 4 thyme sprigs
• 2 (14- to 16-ounce) cans black beans, drained
• 1 cup canned diced tomatoes with their liquid
• 1 chipotle chile in adobo, chopped, plus 1 teaspoon adobo sauce
• 2 large garlic cloves, finely grated or minced
• 1 teaspoon dried oregano
• 3/4 teaspoon ground cumin
• 8 (6-inch) corn tortillas
• 1 lime
• Sliced avocado, for serving
• Crumbled queso fresco or grated white Cheddar, for serving (optional)
• Chopped cilantro leaves, for serving