Preheat oven to 300 degrees F (150 degrees C).
Peel Pumpkin (3 pound) using a vegetable peeler and cut off stem.
Cut in half vertically and scoop out seeds, reserve seeds for roasting if desired.
Cut into approximate 1 1/2-inch chunks and place on a parchment lined baking sheet.
Remove stem from Roma Tomato (1 pound) and cut into quarters.
Spread out on a parchment lined baking sheet. Drizzle the pumpkin and tomatoes with Olive Oil (4 tablespoon) and roast in preheated oven for 1 1/2 hours. Add Garlic (2 clove) to the tray during the last 1/2 hour.
Peel and chop Onion (1) into 1/2-inch chunks. Heat 2 tbsp olive oil in a large soup pot or dutch oven over medium heat, add onion and sauté until starting to soften, approximately 5 minutes.
To the pot add roasted vegetables, Chicken Broth (4 cup), Fresh Oregano (1 tablespoon), Smoked Paprika (1/2 teaspoon), Dry Mustard (1/2 teaspoon), Dried Sage (1/4 teaspoon), Salt (1/2 teaspoon), Ground Black Pepper (1/2 teaspoon), Chili Powder (1/4 teaspoon), and Crushed Red Pepper Flakes (1 pinch). Cover and simmer for a minimum 30 minutes.
Remove from heat and blend with a hand held emersion blender until smooth. Adjust consistency using Chicken Broth (1 cup). Adjust seasoning if desired.
Combine All-Purpose Flour (1 tablespoon), Corn Starch (1 tablespoon), Salt (1/4 teaspoon), and Ground Black Pepper (1/4 teaspoon) in a shallow dish.
Trim ends from Leek (1) and rinse well, making sure to rinse under any loose leaves. Cut leek into 1/4 inch slices and separate rings.
Toss leek slices in flour mixture to gently coat.
Add Canola Oil (1 cup) to a shallow pot or skillet and heat until the oil sizzles when a sprinkle of flour is added. Scoop out half of the leek slices, shake off any excess flour, and add to oil.
Fry for 4-5 minutes until golden, turning once. Using a slotted scoop remove leeks from oil and allow to drain on a paper towel lined plate. Repeat the frying process with remaining leeks. Keep uncovered at room temperature until ready to use.
Ladle soup into serving bowls. Swirl a dab of Sour Cream (9 tablespoon) into each and top with crispy leeks.