Optional: 1 teaspoon flaky sea salt, for sprinkling
Line a 9x13 inch baking pan with foil or parchment paper, allowing two of the sides to overlap; set aside.
To roast the almonds:
Preheat oven to 350 degrees (F).
Spread the almonds in an even layer on a small baking sheet or cake tin. Place in preheated oven and roast for 5 minutes. Remove after 5 minutes and stir. Return to the oven and roast for another 3 to 4 minutes, or until they've become a few shades darker and smell nutty. If they need longer, give them another stir. I find my almonds are perfectly roasted right around 9 minutes, but yours may be done a few minutes earlier/later depending on your oven.
Once sufficiently roasted, remove from the oven and immediately transfer them onto a large plate to cool completely. Once cool, finely chop the almonds into bits.
To melt the chocolate:
Place 3/4 cup of water in a small saucepan and bring to a simmer. Place the chopped chocolate in a heatproof medium bowl, then set the bowl over the saucepan until the chocolate is completely melted. Remove from heat. Add in 1 cup of the nuts and 3/4 cup of toffee and stir quickly to combine.
Spread the chocolate-nut mixture on prepared baking sheet. Top with the reserved almonds and toffee; sprinkle with salt if using. Chill until chocolate is set, about 3 hours. Chop into pieces and serve.