Preheat your oven to 400°F (200°C). Line a large baking sheet with parchment paper.

Place the trimmed and halved Brussels sprouts on the baking sheet. Drizzle with olive oil and season with salt and black pepper. Toss well to coat, then arrange them cut-side down for better caramelization.

Roast for 20-25 minutes, or until the sprouts are tender and the edges are golden brown and crispy.

While the sprouts roast, place a large skillet over medium heat. Add the chopped beef bacon. Fry until distinctively crispy and the fat has rendered. Remove the crispy beef with a slotted spoon and set aside on a paper towel, leaving about 1 tablespoon of the rendered fat in the pan.

In the same skillet with the reserved fat, add the minced garlic and sauté for 30 seconds until fragrant.

Lower the heat to low-medium. Pour in the heavy cream, Dijon mustard, and whole grain mustard. Whisk gently and simmer for 2-3 minutes until the sauce slightly thickens. Stir in the lemon juice.

Remove the skillet from heat. Add the roasted Brussels sprouts to the pan and toss gently to coat them in the creamy mustard sauce.

Transfer to a serving dish. Top generously with the reserved crispy beef and garnish with fresh chopped parsley. Serve immediately.