1. Start by gathering all the ingredients you will need for making the salted chocolate English toffee:
• 1 cup unsalted butter
• 1 cup granulated sugar
• 1/4 teaspoon salt
• 1 teaspoon vanilla extract
• 1 cup semisweet chocolate chips
• 1/2 cup chopped nuts (optional)
• Sea salt for sprinkling
2. Prepare a baking sheet by lining it with parchment paper or a silicone baking mat.
3. In a heavy-bottomed saucepan, melt the butter over medium heat. Stir in the granulated sugar and salt until well combined.
4. Continue to cook the mixture, stirring constantly, until it reaches a temperature of 285°F (140°C) on a candy thermometer. This will take about 10-15 minutes.
5. Remove the saucepan from heat and stir in the vanilla extract. Be careful, as the mixture will bubble up.
6. Pour the hot toffee mixture onto the prepared baking sheet, spreading it out evenly with a spatula.
7. Allow the toffee to cool and harden completely, which usually takes about 1-2 hours.
8. In the meantime, melt the semisweet chocolate chips in a microwave-safe bowl in 30-second intervals, stirring in between, until smooth and fully melted.
9. Once the toffee has hardened, pour the melted chocolate over the top, spreading it evenly with a spatula.
10. If desired, sprinkle chopped nuts over the melted chocolate before it sets.
11. Finish by sprinkling sea salt over the top of the chocolate for that delightful salty-sweet flavor combination.
12. Allow the chocolate to set completely, which usually takes about 1 hour at room temperature or 15-20 minutes in the refrigerator.
13. Once the chocolate has hardened, break the toffee into bite-sized pieces.
14. Your homemade salted chocolate English toffee is now ready to be enjoyed! Store it in an airtight container at room temperature for up to 2 weeks.

For further guidance and visual reference, you can also check out this step-by-step guide with images.

Now go ahead and indulge in the deliciousness of your homemade salted chocolate English toffee!