Grease a 10 x 15 inch jelly roll pan with 2 tablespoons of butter.

Melt 1 cup of butter in a deep, heavy saucepan over medium heat.

Add 1 1/4 cups of sugar, 2 tablespoons of water, and 1/8 teaspoon of salt to the melted butter.

Cook the mixture, stirring until the sugar is dissolved.

Bring the mixture to a boil, then simmer, stirring frequently, until it reaches 300°F on a candy thermometer and is the color of a brown paper bag (about 5-6 minutes).

Remove the saucepan from the heat.

Stir in 1/4 cup of slivered almonds.

Pour the toffee mixture into the prepared jelly roll pan.

Smooth the top of the toffee with a buttered heat-proof spatula.

Use a paper towel to carefully blot the top of the toffee to remove any excess butter.

Immediately scatter 1 cup of high-quality chocolate chips on top of the hot toffee.

Let the chocolate chips stand until melted, about 1 minute.

Spread the melted chocolate evenly over the top of the toffee.

Cool the toffee to room temperature.

Chill the toffee in the refrigerator for 20 minutes.

Break the chilled toffee into pieces.

Layer the toffee pieces between wax paper in an airtight container.

Store the toffee in the refrigerator for up to 2 weeks.