Preheat your oven to 400°F (200°C). Slice the top off the head of garlic to expose the cloves. Drizzle with 1 tablespoon of olive oil and wrap in foil. Roast for about 40 minutes or until the cloves are soft and golden. Once cool, squeeze the roasted garlic cloves out of their skins into a small bowl and mash to a paste.
While the garlic roasts, trim the ends off the green beans and rinse them under cold water. Pat dry thoroughly. In a mixing bowl, toss the green beans with the remaining 1 tablespoon of olive oil, salt, and pepper until evenly coated.
Heat a dry skillet over medium heat. Add the chopped almonds and toast, stirring frequently, until fragrant and lightly browned, about 3-5 minutes. Remove from heat and set aside to cool.
Spread the green beans in a single layer on a parchment-lined baking sheet. Roast in the oven at 400°F (200°C) for 15-20 minutes, tossing halfway through, until tender-crisp and slightly blistered.
Transfer the roasted green beans to a serving bowl. Stir in the mashed roasted garlic, lemon zest, and lemon juice. Toss until everything is well combined. Sprinkle the toasted almonds on top and give a gentle toss or simply scatter them over as a crunchy garnish.
