Mash strawberries in a large bowl using a potato masher or fork. Add sugar, pectin and lemon juice. Stir well. Pour mixture into a 12-inch nonstick skillet and boil until slightly thickened, about 5 minutes. Remove from skillet and pour into a bowl to cool. Once jam is at room temperature, cover tightly and refrigerate until ready to serve. Makes about 1 1/4 cups. Jam will keep, chilled in an airtight container, for 2 weeks.