Early breakfasting in Negombo isn't the easiest as most of the places tend to open late (mostly after 10 AM). So unless you're going with a B&B, you might find yourself wandering around the streets looking for food.
Going through the same scenario, we ended up at Ruki Sea Reach, a small cafe down Lewis Place which also has a guest house of their own as well.
Food
The Continental Breakfast (Rs. 1000) was comprised of an omelette, two slices of toasted sandwich bread, two chicken sausages, a serving of French fries and butter, accompanied with a plate of fruits, and a glass of orange juice.

The plate of fruits included papaya, watermelon and pineapple that had been sitting inside the fridge for a while. Apart from the watermelon, the other two tasted sort of old and had a very frozen texture.
The orange juice was a refreshing treat. There was a bit of sugar involved, but we didn't mind as the natural citrusy notes managed to emerge through every sip.
For Rs. 600, the French Toast at Ruki Sea Reach was nothing extraordinary. There were two slices of sandwich bread soaked in milk and a lot of honey; making things sweeter than it should.
Drinks
Frothy, light, not bitter nor burnt, the Cappuccino (Rs. 400) by Ruki Sea Reach is strong enough to pick up the poor soul of someone who's suffering from a massive hangover. A little more velvetiness in the milk would have made it better though.

Ambience & Service
Like we stated previously, this cafe is a part of their guest house and it's managed by a family. The interior is quite simple with a few wooden tables and chairs, and they've got outdoor seating too, if you don't mind all the hustle and noise down the road.
The servers were full of smiles but lacked efficiency. Our order was taken three times, and yet there was a muddle up in the items. We received a latte instead of a hot chocolate, and there was the incident where they totally forgot about the French Toast. The food took more than 30 minutes to arrive, which is not quite convenient given that we were the only customers they had at the time.
Conclusion
All in all, it's quite all right. If you're an early bird who's looking for breakfast at 9.00 AM in Negombo, Ruki Sea Reach serves as an option.