Place celery stalks, carrot, quartered onion, unpeeled garlic cloves, bay leaves, fresh thyme, parsley, and peppercorns in a large stock pot. Add 3 quarts of cold water, then gently lower the whole chicken into the pot. Bring to a gentle simmer over medium heat, then reduce to low. Let it cook uncovered for about 90 minutes, skimming any foam that rises to the surface occasionally.

Carefully remove the cooked chicken from the pot using tongs and place it on a large cutting board. Allow it to cool for 10-15 minutes until safe to handle. Shred the meat using two forks or your hands, discarding the skin and bones. Set the shredded chicken aside in a bowl.

Strain the chicken stock through a fine-mesh strainer into a large bowl or another pot, discarding all the vegetables and aromatics. Skim off any excess fat from the surface using a ladle or fat separator. You should have about 8-10 cups of flavorful stock.

Slice the corn tortillas into thin strips, about 1/4-inch wide. Heat about 1/2 inch of vegetable oil in a frying pan over medium-high heat until shimmering. Fry the tortilla strips in small batches for 1-2 minutes until golden and crispy, being careful not to burn them. Remove with a slotted spoon and drain on paper towels. Season lightly with salt while still hot.

In the same large pot you used for the stock, heat 2 tablespoons of vegetable oil over medium heat. Add diced onion and green bell pepper, cooking for 5-7 minutes until softened and slightly golden. Add minced garlic and stir for one minute until fragrant.

Mix in the fire-roasted diced tomatoes, ground cumin, dried oregano, chili powder, and smoked paprika. Stir everything together and cook for 2-3 minutes until the spices become fragrant and coat the vegetables.

Pour the strained chicken stock back into the pot. Add drained black beans, corn kernels, and the shredded chicken. Bring everything to a gentle simmer and cook for 10 minutes, allowing all the flavors to meld together. Stir in fresh lime juice and chopped cilantro. Taste and adjust seasoning with salt and black pepper.

Ladle the hot saltgrass chicken tortilla soup into bowls. Top each serving generously with crispy tortilla strips, a dollop of sour cream, cubed avocado, radish slices, fresh jalapeño, shredded cheese, and a lime wedge on the side. Serve immediately while hot.