Preheat the oven to 350°F (180°C). Wrap both garlic heads separately in foil and place them on a baking sheet. Roast for 20–25 minutes, or until the cloves feel completely soft.

Bring a large pot of salted water to a rolling boil. Add the trimmed green beans and cook for 1½–2 minutes. They should become bright green while still retaining a crisp bite.

Transfer the beans immediately to a colander and rinse them under very cold running water. This stops the cooking process and preserves their color. Drain thoroughly so the dressing doesn’t become watery.

Add the flaked almonds to a dry skillet over medium heat. Toast them for 2–3 minutes, stirring frequently, until lightly golden and fragrant. Remove them promptly to prevent burning.

Once the roasted garlic is cool enough to handle, squeeze the soft cloves into a mixing bowl and mash until smooth. Whisk in the vinegar, Dijon mustard, honey, olive oil, salt, and pepper.

Taste the mustard dressing before using it. Add a small drizzle of honey if it tastes too sharp, or another splash of vinegar if it needs more brightness.

Place the drained green beans in a large serving bowl. Pour over enough mustard dressing to coat them lightly, then toss gently until the beans are evenly covered.

Fold in most of the toasted almonds shortly before serving so they remain crunchy. Sprinkle the remaining almonds over the top and serve the green beans slightly warm or at room temperature.