Fry nuts in a little olive oil. When brown and fragrant, add thyme, give it a few tosses, then remove the nuts with a slotted spoon to a paper towel. Transfer again to a small bowl and while still warm toss with brown sugar, salt and cayenne. Reserve.
Bring a large pot of heavily salted water to a boil. Cut the Brussels sprouts in half and peel the bright green outer leaves. Reserve both separately.
Blanch the Brussels sprouts for 2 minutes until bright green and tender. Drain, shock in ice water, drain again and reserve.
In a large sauté pan, melt 2 Tbsp of the bacon fat over low heat and add the reserved outer leaves of Brussels sprouts, taking care not to burn, cool slowly, turning occasionally until leaves become quite crisp. Remove to a paper towel and season with a little salt and pepper. Reserve.
Heat a sauté pan over med-high heat and swirl in remaining bacon fat. when hot, add the halved sprouts, cut side down, to fill the pan. Cook until brown and caramelized, then add the chicken stock and reduce liquid to a scant amount. Reduce heat and add butter to make a sauce. Squeeze half a lemon over the Brussels sprouts.
Toss in bacon and nuts. Serve immediately.
Nutrition Info Per Serving: Calories 351 Total Fat 34 g Cholesterol 25 mg Sodium 302 mg Potassium 395 mg Total Carbohydrate 7 g Dietary Fiber 3 g Sugars 3 g Protein 7 g