Preheat oven to 300°F.
Melt butter in a microwave-safe dish for 30 seconds on high, then stir in stevia.
Toss pecan halves with the butter mixture until fully coated.
Spread pecans on a non-stick baking sheet, preferably lined with a silicone baking mat.
Bake 18 to 22 minutes, stirring halfway, and watch closely during the final 5 minutes.
Transfer toasted pecans to a large bowl.
Put chocolate chips in a large microwave-safe bowl.
Microwave at 50% power for 1 minute; stir thoroughly to distribute heat.
Microwave at full power in 15-second increments, stirring after each, until nearly melted.
Stir in coconut oil until smooth.
Stir pecans into the chocolate until completely coated.
Lift pecans with a fork onto a lined baking sheet, leaving space between pieces.
Refrigerate at least 30 minutes.
Serve chilled and store remaining pecans in the refrigerator or freezer.