Berries:
In large bowl, mix together berries. Pour Grand Marnier over the top. Sprinkle with sugar. Mix to evenly coat berries. Place in fridge for one hour, stirring occasionally. Keep chilled
Crepes:
Place oil in large nonstick skillet and heat over low for at least 10 minutes to throughly heat the pan.
In large bowl whisk together flour, sugar, and salt. In separate bowl, whisk together milk and eggs. Add half of milk mixture to dry ingredients and whisk until smooth. Add butter and whisk until incorporated. Whisk in other half of the milk/egg mixture until smooth and fully incorporated.
With a paper towel spread heated oil around the non-stick skillet. Increase heat to medium and let skillet heat for 1 more minute. Test heat of skillet by placing 1 teaspoon batter in center and cook for 20 seconds. If mini crêpe is golden brown on bottom, skillet is properly heated; if the crepe burns or does not brown, adjust the heat of the skillet to accommodate.
4. Pour 1/4 cup batter into far side of pan and swirl gently until batter evenly covers bottom of pan. Cook crêpe without moving it until top surface is dry and crêpe starts to brown at edges, loosening crêpe from side of pan with rubber spatula, about 25 seconds. Gently slide spatula underneath edge of crêpe, grasp edge with fingertips, and flip crêpe. Cook until second side is lightly spotted, about 20 seconds. Transfer cooked crêpe to wire rack, inverting so spotted side is facing up. Return pan to heat and heat for 10 seconds before repeating with remaining batter. Place the done crepes on a wire rack to cool and allow steam to wear off.
When done plate the crêpes on a large microwave-safe plate and invert second plate over crêpes. Microwave on high power until crêpes are warm, 30 to 45 seconds (45 to 60 seconds if crêpes have cooled completely). Remove top plate and wipe dry with paper towel.