In a large bowl, combine 2 lbs chicken tenders, 1 cup buttermilk, 1 egg, 1 tbsp kosher salt, 1 tbsp paprika, 1 tbsp black pepper, 2 tsp garlic powder, and 2 tsp dried oregano. Cover and refrigerate overnight.
To make the basil cream sauce, add ½ cup yogurt, ½ cup sour cream, 1 cup basil, ¼ cup dill, ½ tbsp honey, 1 garlic clove, 1 tbsp distilled white vinegar, 1 tbsp olive oil, 1 tbsp onion powder, ½ tsp garlic powder, 1 tsp salt, and ½ tsp lemon juice to a blender or food processor. Blend until smooth and refrigerate until ready to serve.
Preheat the oven to 450°F (232°C). Line a sheet pan with parchment paper.
Fill a large pot with water and add 3 tbsp sea salt or 4 tbsp kosher salt. Bring to a boil.
Add the potatoes and boil for 8 minutes.
Drain the potatoes and allow them to steam dry for 5 minutes.
Transfer the potatoes to a large bowl. Add 2 tbsp sage, 1 tsp salt, and ¼ cup olive oil. Toss vigorously to rough up the edges.
Spread the potatoes onto the prepared baking sheet and roast for 25 minutes. Flip and roast for another 20 to 25 minutes, or until deeply golden and crispy.
In a shallow bowl, whisk together 1½ cups flour, ½ cup cornstarch, 1 tsp baking powder, and 2 tsp kosher salt.
Remove the chicken from the marinade. Coat each tender in the flour mixture, pressing firmly so the breading adheres well.
Heat about 2 inches of oil in a deep cast iron skillet or Dutch oven to 390°F (199°C).
Carefully add the chicken. The oil temperature should drop to around 360°F (182°C).
Fry for 3 minutes without disturbing. Start moving the tenders around gently in the hot oil to cook them evenly, one more minute.
Flip and continue frying for 4 more minutes, gently moving the tenders as needed, until golden brown and cooked through.
Transfer the chicken to a paper towel lined plate if serving immediately. If holding for later, place on a wire rack and keep warm in a 300°F (149°C) oven.
Serve the fried chicken tenders with the crispy sage potatoes, basil cream sauce, and a simple green salad.