As a big guy, I'd use a spiral ride, with the claw to create space. If that isn't working, place your same side knee next to his, chop his arm and pull him with a tight waist over your knee. You just have to make sure to get your hips out from under his and square them to the mat as soon as you feel him crossing your knee. Otherwise, you risk having him high leg over you and get the reversal with possible back points. The third option on the mat, and not one I'd recomend to 90% of big men who aren't already decent leg riders, is to learn to crab ride and pull him back into the crab. One other breakdown I've used, but one I wouldn't recommend as a first option is as follows: If you're on his left side, grab is right foot or ankle (or at least block it) with your right hand, at the same time reach under his stomach and block his right knee with your left hand. You'll end up with your left shoulder in his ribs and you'll be perpendicular to the way he's facing. Now just drive your legs to drive him off of his base and onto his right hip.
Of course another option is to just kick him out and take him down and break him down off of the takedown. That's usually what I did against guys like that. Eventually, you'll be able to transition to something to turn him with right off of a takedown. That's especially true in practice, when there's no ref to call stalling. Neither of you is getting any better, by sitting there, so you might as well work on your takedowns. Practice is about getting better, not about winning, so put yourself in positions you wouldn't during a match, or try stuff you haven't perfected.